Ballistics by the inch

Do you want good data, or useable data?

Got a question I haven’t seen for a while. Here it is, with my answer (and a little bit of additional explanation) to follow:

Thanks for the site!  You do not post the altitude and  temperature of your results (unless I missed that).  Can you let us know what your reference points are?  Also, what effect would altitude and temperature variation have on your results?

Here’s the answer I gave:

Well, it’s been a while since anyone asked about that … thanks!

We did discuss this early on, and decided pretty quickly that while both of those would indeed have an effect (as would the changes in barometric pressure), that it would be so small as to not matter for the degree of accuracy of our testing equipment and the limited number of rounds tested. If you were trying to get really good data, everything would have to be much more rigorous and controlled … and we would never ever have gotten the data that we did. So as I remind people: consider the results to be *indicative*, not definitive. In other words, don’t try to read too much into variances of a few feet-per-second, or convince yourself that such minor differences really matter.

Hope that helps to give a little perspective.

Oh, and I can answer one of your questions: almost all the testing was done at an elevation of approximately 744′ above sea level, according to commercial GPS systems.

I think that’s pretty clear, but I want to emphasize one part of it: that if we had set out to provide really rigorous and statistically-significant data, the chances are that we would never have even gotten past the first test sequence. And that means there would be NO BBTI.

As it is, we have tested something in excess of 25,000 rounds over the last 7 years. At a personal cost of more than $50,000. And that doesn’t begin to include the amount of labor which has gone into the project. To get really solid data which was statistically significant, we probably would have needed to do at LEAST three or four times as many rounds fired. With three or four times the amount of time testing. And crunching the data. And cost out of pocket.

Which would have meant that we probably would never have gotten through a single test sequence.

So it’s a matter of perspective. Do you want some data which is reasonably solid, and gives a pretty good idea of what is going on with different cartridges over different barrel lengths? Or do you want very accurate, high rigorous data which would never have been produced?

Hmm … let me think about that … ;)

 

Jim Downey

PS: We haven’t forgotten about the .45 Super/.450 SMC tests — it’s just been a busy summer. Look for it soon.

August 11, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, .460 Rowland, Data, Discussion., General Procedures | , , , , , , , , , , , , , , | Leave a comment

Some “Super” performance out of a Cx4 Storm.

This is the fourth in a series of informal blog posts about the .45 ACP/Super/.450 SMC testing sequence we conducted over the Memorial Day weekend. You can find the previous posts herehere, and here.

Today we’re going to look at the results out of a stock Beretta Cx4 Storm in (obviously) .45 ACP. I have previously reviewed the Cx4 Storm in .45 ACP for Guns.com, and it is a great little pistol caliber carbine with a 16.6″ barrel. Here is Keith shooting the one we used for this recent testing:

Cx4

I want to re-iterate that the Cx4 was completely stock, with no modifications or additions whatsoever for these tests.

As I said with the previous posts about these tests, it’ll be a while before we have all the data crunched and the website updated, but I thought I would share some preliminary thoughts and information through a series of informal posts.

Quick note about the data below: All the ammo used, with the exception of the four * items, were part of our overall test sequence and had three shots made over the Oehler chronograph (which is a double-unit, and automatically records and then averages the two readings), representing a total of 6 data points. I’m just giving the overall averages here; the full data will be available on the website later. The four * ammunition types only include two shots/four data points through the Cx4. That’s because we only had one box of each of this ammo, and were wanting to get data which would be of the greatest use to the largest number of people.

 

Ammo                                                                               Cx4 Storm

      Buffalo Bore

.45 ACP Low Recoil Std P 185gr FMJ-FN                 997 fps / 408 ft-lbs

.45 ACP Std P 230gr FMJ-RN                                933 fps / 444 ft-lbs

.45 ACP +P 185gr JHP                                       1361 fps / 760 ft-lbs

.45 ACP +P 230gr JHP                                       1124 fps / 645 ft-lbs

.45 Super 185gr JHP                                         1555 fps / 993 ft-lbs

.45 Super 200gr JHP                                         1428 fps / 905 ft-lbs

.45 Super 230gr FMJ                                         1267 fps / 819 ft-lbs

.45 Super 230gr JHP                                         1289 fps / 848 ft-lbs

.45 Super 255gr Hard Cast                                 1248 fps / 881 ft-lbs

      Double Tap

.45 ACP +P 160gr Barnes TAC-XP                        1315 fps / 614 ft-lbs

.450 SMC 185gr JHP                                          1618 fps / 1075 ft-lbs

.450 SMC 185gr Bonded Defense JHP                  1556 fps / 994 ft-lbs

.450 SMC 230gr Bonded Defense JHP                  1298 fps / 860 ft-lbs

      Hornady

Critical Defense .45 ACP Std P 185gr FTX              1161 fps / 553 ft-lbs

Critical Duty .45 ACP +P 220gr Flexlock                 1018 fps / 506 ft-lbs

      Underwood

.45 Super 170gr CF                                           1421 fps / 762 ft-lbs

.45 Super 185gr XTP JHP                                   1578 fps / 1022 ft-lbs

.45 Super 230gr GD JHP                                     1264 fps / 815 ft-lbs

*Federal  HST .45 ACP Std P 230gr JHP                882 fps / 397 ft-lbs

*G2 Research  RIP  .45 ACP Std P 162gr JHP        979 fps / 344 ft-lbs

*LeHigh Defense .45 Super 170gr JHP               1289 fps / 627 ft-lbs

*Liberty  Civil Defense .45 ACP +P 78gr JHP        2180 fps / 822 ft-lbs

 

Something in particular I want to note: that in comparison to .45 ACP loads (whether standard pressure or +P), a number of the .45 Super/.450 SMC loads gain significantly more from the longer barrel. Compare these numbers to the previous posts of handguns, and you can see what I mean. You typically only gain about 10 – 15% in terms of velocity from the .45 ACP loads in going to a carbine — and this is very much in keeping with our previous testing of that cartridge. But you see upwards of a 30% gain in velocity out of some of the .45 Super/.450 SMC loads … and that translates to a 50% increase in muzzle energy!

A heavy, large projectile hitting with 900 – 1,000 foot-pounds of energy is nothing to sneeze at. Particularly when it comes with very little felt recoil out of this little carbine. That means you can get quick and accurate follow-up shots, which is always an advantage when hunting or using a gun for self/home defense.

As noted previously, we noticed no unusual wear on the Cx4 Storm, though a steady diet of such ammo could increase wear on the gun over time. And the Beretta didn’t have any problems whatsoever feeding, shooting, or ejecting any of the rounds. Where we had experienced some problems with the same ammo out of some of the handguns, there wasn’t a hiccup with the Cx4 Storm.

Look for more results, images, and thoughts in the days to come.

 

Jim Downey

June 16, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , , | 7 Comments

Ammo test results for a pair of 1911s

This is the third in a series of informal blog posts about the .45 ACP/Super/.450 SMC testing sequence we conducted over the Memorial Day weekend. You can find the previous posts here and here.

Today we’re going to see what the results are for a couple of different high-end 1911 platform guns. The first is an Ed Brown Kobra Carry (reviewed here), a Commander-sized (4.25″ barrel) single stack designed as a concealed-carry gun. We made no modifications of it for the more powerful loads. Here it is during our testing:

 

Ed Brown

The second is a Wilson Combat Hunter set up for the .460 Rowland cartridge with a 5.5″ barrel. Here’s my review of it, and here it is on the day of testing:

Wilson hunter

As I said with the other two posts about these tests, it’ll be a while before we have all the data crunched and the website updated, but I thought I would share some preliminary thoughts and information through a series of informal posts.

Quick note about the data below: All the ammo used, with the exception of the four * items, were part of our overall test sequence and had three shots made over the Oehler chronograph (which is a double-unit, and automatically records and then averages the two readings), representing a total of 6 data points. I’m just giving the overall averages here; the full data will be available on the website later. The four * ammunition types only include two shots/four data points through the Ed Brown Kobra Carry,  since it is a typical length for a self-defense gun. That’s because we only had one box of each of this ammo, and were wanting to get data which would be of the greatest use to the largest number of people.

 

Ammo                                                         Ed Brown Kobra Carry              Wilson Combat Hunter

      Buffalo Bore

.45 ACP Low Recoil Std P 185gr FMJ-FN                 798 fps / 261 ft-lbs                       791 fps / 256 ft-lbs

.45 ACP Std P 230gr FMJ-RN                                811 fps / 335 ft-lbs                       819 fps / 342 ft-lbs

.45 ACP +P 185gr JHP                                       1130 fps / 524 ft-lbs                     1139 fps / 532 ft-lbs

.45 ACP +P 230gr JHP                                        952 fps / 462 ft-lbs                       970 fps / 480 ft-lbs

.45 Super 185gr JHP                                         1257 fps / 648 ft-lbs                     1312 fps / 706 ft-lbs

.45 Super 200gr JHP                                         1175 fps / 613 ft-lbs                     1216 fps / 656 ft-lbs

.45 Super 230gr FMJ                                         1067 fps / 581 ft-lbs                     1105 fps / 623 ft-lbs

.45 Super 230gr JHP                                         1084 fps / 600 ft-lbs                     1109 fps / 627 ft-lbs

.45 Super 255gr Hard Cast                                 1061 fps / 637 ft-lbs                     1074 fps / 653 ft-lbs

      Double Tap

.45 ACP +P 160gr Barnes TAC-XP                        1121 fps / 446 ft-lbs                     1162 fps / 479 ft-lbs

.450 SMC 185gr JHP                                          1310 fps / 704 ft-lbs                     1350 fps / 748 ft-lbs

.450 SMC 185gr Bonded Defense JHP                  1254 fps / 645 ft-lbs                     1294 fps / 687 ft-lbs

.450 SMC 230gr Bonded Defense JHP                  1103 fps / 621 ft-lbs                     1108 fps / 626 ft-lbs

      Hornady

Critical Defense .45 ACP Std P 185gr FTX               969 fps / 385 ft-lbs                       976 fps / 391 ft-lbs

Critical Duty .45 ACP +P 220gr Flexlock                  932 fps / 424 ft-lbs                       936 fps / 427 ft-lbs

      Underwood

.45 Super 170gr CF                                           1249 fps / 588 ft-lbs                     1259 fps / 598 ft-lbs

.45 Super 185gr XTP JHP                                   1285 fps / 678 ft-lbs                     1339 fps / 736 ft-lbs

.45 Super 230gr GD JHP                                     1071 fps / 585 ft-lbs                    1099 fps / 616 ft-lbs

*Federal  HST .45 ACP Std P 230gr JHP                815 fps / 339 ft-lbs

*G2 Research  RIP  .45 ACP Std P 162gr JHP        961 fps / 332 ft-lbs

*LeHigh Defense .45 Super 170gr JHP               1165 fps / 512 ft-lbs

*Liberty  Civil Defense .45 ACP +P 78gr JHP         1843 fps / 588 ft-lbs

 

As with the other guns I’ve posted about, the general trends are pretty clear with the power rising as you go from standard pressure to +P to Super/.450 SMC, and topping out at about 750 foot-pounds of energy in a couple of loads. And it is interesting to note that the 185gr loads seem to be the “sweet spot” in terms of power across the board.

Of course, pure power is just one component for what makes a good ammunition choice. Bullet design & penetration is extremely important when considering a self-defense load. Shootability in your gun is also critical — because if you can’t recover quickly from shot to shot, then you may limit your ability in a stressful situation. Likewise, if the ammo doesn’t function reliably, or damages your gun, that is also a huge factor.

Most of the ammo we tested functioned very well in both 1911 platforms.  Interestingly, while we had experienced FTFs (failure-to-fire) with a number of the different Double-Tap rounds in both the Bobergs and the Glocks, we didn’t experience any such problems with either 1911.

The larger platform of the Wilson Combat Hunter handled the recoil very well, even from the hottest loads. Recoil was a little more noticeable with the Ed Brown, but only by a slight amount. As I noted with the Glock 21 converted for the .460 Rowland,  I was impressed that The Wilson Combat Hunter didn’t have any problems cycling even the lightest loads reliably.

Another note: we were unable to detect any damage or unusual wear to either gun, though it is possible a steady diet of loads of that power could cause some over the long term.

Lastly, I ran some .460 Rowland Buffalo Bore 230gr JHP cartridges through the Wilson Combat Hunter, since we had only had one type of ammo for that gun when we did the .460 Rowland tests.  That had been Cor-Bon Hunter 230gr JHP. The Cor-Bon tested at 1213 fps / 751 ft-lbs, and the Buffalo Bore tested at 1349 fps / 929 ft-lbs of energy.

Look for more results, images, and thoughts in the days to come.

 

Jim Downey

June 9, 2015 Posted by | .45 Colt, .45 Super, .450 SMC, .460 Rowland, Boberg Arms, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 2 Comments

“How can I use your data?”

We get a fair number of questions to the BBTI email account ( info@ballisticsbytheinch.com ), which I try to answer as quickly as my time will allow. Most are about specific points in our data, or why we did this or that in our procedures (answers to most such can be found in our FAQ). But every once in a while a question comes along which pushes me to re-think things from another vantage point. The following is one such from “drglenn”, and I thought I would share it and my answer:

Found your website interesting, but I am uncertain how I can use this data reliably for me. Perhaps you can offer some guidance. Clearly, barrel length data can be used relatively to compare any single caliber/brand/bullet mass to itself. This is useful to see muzzle velocities/energy as a function of barrel length which might help the consumer in determining just how much more value they will get by purchasing a longer barreled firearm. What I found frustratingly non-useful is an inability to compare bullet mass to velocity/energy across brands – or even within a single brand – of stock ammo. This, no doubt, is a function of powder composition, cartridge air-space volume, and quantity of said powder. One might reasonably assume that, every other parameter being equal, a bullet with more mass, will have a lower muzzle velocity. One might also reasonably assume that since E=1/2mv^2, that velocity is much more significant than bullet mass in determining energy (i.e., all else being equal, if you could double the velocity, you would get 4x the energy, while doubling the mass will only yield twice the energy). Apparently, this useful bit of physics becomes completely useless as each manufacturer uses different powder formulations and quantities for their ammo. So, while I may be able to determine that, across the board, a certain mass bullet or higher, in a certain caliber, regardless of manufacturer, may be subsonic, it would be a crap-shoot in guessing which mass and which manufacturer should have the highest muzzle energy in a given barrel length.

Suggestions for best use of your data would be appreciated!

Sorry, I’m not quite sure what you’re asking. You’re correct that because of proprietary powder formulations, there’s no easy comparison between different manufacturers or even between different ‘lines’ of product from a given manufacturer. In fact, the situation is even much worse than you state, because the manufacturers are *constantly* tweaking their formulations in an effort to claim more of the market. And then there’s the whole matter of terminal ballistic performance depending on the actual bullet design and composition. Toss in the fact that firearms manufacturers are also constantly making minor alterations to their models and production methods, and yeah, it’s impossible to say with any certainty that this or that combination of gun and ammo will give a reliable result. In short, there is no “perfect” solution to the very complex problems of ballistics — one of the reasons why it has a long history of attracting some of the finest minds in physics.

But you can gain insight in what to expect within certain parameters using our data. You can see that while most semi-auto handgun ammunition performs best in a certain range of barrel lengths — usually from 3″ to 8″ –, that ‘magnum’ rounds intended primarily for revolvers will continue to gain velocity/energy over a much longer range of barrel lengths, and so is more suitable for a carbine. You can tell that most ammo formulated to be “low recoil” means that it has less overall velocity/energy, since you can’t break the laws of physics. You can see that some manufacturers may claim performance standards which aren’t supported by our tests, and some are right on the money. You can argue with your friends over a beer whether it is better to use a slow heavier bullet or a lighter one which goes much faster.

In short, our data is a tool for helping analysis and decision-making, nothing more. It’s certainly not perfect. It’s not even comprehensive within a given caliber/cartridge. And it is in some sense rendered obsolete each and every time the manufacturers tweak their production materials or methods. Which is why we always tell people to consider it indicative, not definitive. Use it if it makes sense for your needs, don’t if it doesn’t. And always – ALWAYS – know that testing your own ammo out of your specific gun is the only way to know for sure how it will perform.

Hope this helps.

Jim Downey

June 4, 2015 Posted by | Data, Discussion., General Procedures | , , , , , , , | Leave a comment

Ammo test results in two versions of the Glock 21

This is the second in a series of informal blog posts about the .45 ACP/Super/.450 SMC testing sequence we conducted over the Memorial Day weekend. You can find the previous post here.

Here’s a pic of getting set the first day of shooting:

getting set

As noted previously, it’ll be a while before we have all the data crunched and the website updated, but I thought I would share some preliminary thoughts and information through a series of informal posts. In this second post, we’ll see how two different versions of a Gen 4 Glock 21 performed with the ammo. The first version was with the Glock in the standard .45 ACP configuration, the second was with my .460 Rowland conversion kit in place.

The standard configuration has a 4.61″ octagonal polygonal rifling, while the conversion barrel is 5.2″ overall with conventional rifling, threaded, and with a compensator. The .460 conversion also has a heavier recoil spring.

Quick note about the data below: All the ammo used, with the exception of the four * items, were part of our overall test sequence and had three shots made over the Oehler chronograph (which is a double-unit, and automatically records and then averages the two readings), representing a total of 6 data points. I’m just giving the overall averages here; the full data will be available on the website later. The four * ammunition types only include two shots/four data points through the standard Glock 21 configuration — we only had one box of each of this ammo, and were wanting to get data from a range of guns.

Ammo                                                         Glock 21 Standard                   Glock 21 .460 Rowland

      Buffalo Bore

.45 ACP Low Recoil Std P 185gr FMJ-FN                 801 fps / 263 ft-lbs                       792 fps / 257 ft-lbs

.45 ACP Std P 230gr FMJ-RN                                829 fps / 350 ft-lbs                       826 fps / 348 ft-lbs

.45 ACP +P 185gr JHP                                       1132 fps / 526 ft-lbs                     1168 fps / 560 ft-lbs

.45 ACP +P 230gr JHP                                        951 fps / 461 ft-lbs                       974 fps / 484 ft-lbs

.45 Super 185gr JHP                                         1279 fps / 671 ft-lbs                     1299 fps / 693 ft-lbs

.45 Super 200gr JHP                                         1178 fps / 616 ft-lbs                     1203 fps / 642 ft-lbs

.45 Super 230gr FMJ                                         1069 fps / 583 ft-lbs                     1085 fps / 601 ft-lbs

.45 Super 230gr JHP                                         1094 fps / 611 ft-lbs                     1116 fps / 635 ft-lbs

.45 Super 255gr Hard Cast                                 1063 fps / 639 ft-lbs                     1061 fps / 637 ft-lbs

      Double Tap

.45 ACP +P 160gr Barnes TAC-XP                        1103 fps / 432 ft-lbs                     1103 fps / 432 ft-lbs

.450 SMC 185gr JHP                                          1328 fps / 724 ft-lbs                     1351 fps / 749 ft-lbs

.450 SMC 185gr Bonded Defense JHP                  1301 fps / 695 ft-lbs                     1314 fps / 709 ft-lbs

.450 SMC 230gr Bonded Defense JHP                  1097 fps / 614 ft-lbs                     1132 fps / 654 ft-lbs

      Hornady

Critical Defense .45 ACP Std P 185gr FTX               984 fps / 397 ft-lbs                       979 fps / 393 ft-lbs

Critical Duty .45 ACP +P 220gr Flexlock                  945 fps / 436 ft-lbs                       943 fps / 434 ft-lbs

      Underwood

.45 Super 170gr CF                                           1239 fps / 579 ft-lbs                     1253 fps / 592 ft-lbs

.45 Super 185gr XTP JHP                                   1329 fps / 725 ft-lbs                     1348 fps / 746 ft-lbs

.45 Super 230gr GD JHP                                    1075 fps / 590 ft-lbs                     1081 fps / 596 ft-lbs

*Federal  HST .45 ACP Std P 230gr JHP                813 fps / 337 ft-lbs

*G2 Research  RIP  .45 ACP Std P 162gr JHP        942 fps / 319 ft-lbs

*LeHigh Defense .45 Super 170gr JHP              1146 fps / 495 ft-lbs

*Liberty  Civil Defense .45 ACP +P 78gr JHP        1768 fps / 580 ft-lbs

 

As with the Boberg XR45s, the general trends are pretty clear with the power rising as you go from standard pressure to +P to Super/.450 SMC, and topping out at about 750 foot-pounds of energy in a couple of loads. And it is interesting to note that the 185gr loads seem to be the “sweet spot” in terms of power across the board.

Of course, pure power is just one component for what makes a good ammunition choice. Bullet design & penetration is extremely important when considering a self-defense load. Shootability in your gun is also critical — because if you can’t recover quickly from shot to shot, then you may limit your ability in a stressful situation. Likewise, if the ammo doesn’t function reliably, or damages your gun, that is also a huge factor.

Most of the ammo we tested functioned very well in the Glock in either configuration. This isn’t surprising to anyone who has much familiarity with Glocks which typically will handle just about any ammo under all conditions. We did experience FTFs (failure-to-fire) with a number of the different Double-Tap rounds, just as we did in the Bobergs. Those seemed to have been due to light strikes on the primer, which could have been due to improper primer seating, ‘hard’ primers, or some other factor.

The larger platform of the Glock 21 handled the recoil very well, even from the hottest loads. I was impressed that even with the .460 Rowland conversion in place, with the additional weight of the compensator and the heavy recoil spring, the Glock didn’t have any problems cycling even the lightest loads reliably.

One other note: as discussed in my blog post about the .460 Rowland conversion, full-power .460 Rowland loads tend to cause damage to the magazines. As far as we could tell, the same isn’t true of the full-power .45 Super/.450 SMC loads. Just one magazine (a new one) was used for all these tests, and there was no detectable damage. Nor was there any other damage detected to the gun otherwise, though it is possible a steady diet of loads of that power could cause some over the long term.

Look for more results, images, and thoughts in the days to come.

 

Jim Downey

June 1, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, .460 Rowland, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , | 5 Comments

Ammo test results in the Boberg XR45-S

Well, we had a long, but successful, .45 ACP/Super/.450 SMC testing sequence over the memorial day weekend. Here’s a pic of the ammo station showing all the different rounds tested:

Super ammo

It’ll be a while before we have all the data crunched and the website updated, but I thought I would share some preliminary thoughts and information through a series of informal posts. This is the first such, looking at how the ammo performed in a pair of Boberg XR45-S pistols.

As I have noted previously, the Boberg operating mechanism is unusual/unique, with a reverse-feed action. This allows for a more compact design, and changes the felt recoil from what you would expect of most small semi-automatics, and is robust enough to handle full-power .45 Super/.450 SMC cartridges without any alterations. It can, however, present some reliability issues with some ammunition — see the note at the end.

Quick note about the data below: All the ammo used, with the exception of the four * items, were part of our overall test sequence and had three shots made over the Oehler chronograph (which is a double-unit, and automatically records and then averages the two readings), representing a total of 6 data points. I’m just giving the overall averages here; the full data will be available on the website later. The four * ammunition types only include two shots/four data points through one of the Bobergs — we only had one box of each of this ammo, and were wanting to get data from a range of guns.

Ammo                                                               Boberg XR45 A                           Boberg XR45 B

      Buffalo Bore

.45 ACP Low Recoil Std P 185gr FMJ-FN                 749 fps / 230 ft-lbs                       716 fps / 210 ft-lbs

.45 ACP Std P 230gr FMJ-RN                                745 fps / 283 ft-lbs                       766 fps / 299 ft-lbs

.45 ACP +P 185gr JHP                                       1060 fps / 461 ft-lbs                     1052 fps / 454 ft-lbs

.45 ACP +P 230gr JHP                                        902 fps / 415 ft-lbs                       906 fps / 419 ft-lbs

.45 Super 185gr JHP                                         1167 fps / 559 ft-lbs                     1173 fps / 565 ft-lbs

.45 Super 200gr JHP                                         1104 fps / 541 ft-lbs                     1106 fps / 543 ft-lbs

.45 Super 230gr FMJ                                         1008 fps / 518 ft-lbs                     1019 fps / 540 ft-lbs

.45 Super 230gr JHP                                         1034 fps / 545 ft-lbs                     1020 fps / 531 ft-lbs

.45 Super 255gr Hard Cast                                 1017 fps / 585 ft-lbs                     1010 fps / 577 ft-lbs

      Double Tap

.45 ACP +P 160gr Barnes TAC-XP                        1040 fps / 384 ft-lbs                     1047 fps / 389 ft-lbs

.450 SMC 185gr JHP                                          1249 fps / 640 ft-lbs                     1243 fps / 634 ft-lbs

.450 SMC 185gr Bonded Defense JHP                  1244 fps / 635 ft-lbs                     1194 fps / 585 ft-lbs

.450 SMC 230gr Bonded Defense JHP                  1068 fps / 582 ft-lbs                     1046 fps / 558 ft-lbs

      Hornady

Critical Defense .45 ACP Std P 185gr FTX               930 fps / 355 ft-lbs                       937 fps / 360 ft-lbs

Critical Duty .45 ACP +P 220gr Flexlock                  885 fps / 382 ft-lbs                       894 fps / 390 ft-lbs

      Underwood

.45 Super 170gr CF                                           1184 fps / 529 ft-lbs                     1167 fps / 513 ft-lbs

.45 Super 185gr XTP JHP                                   1250 fps / 641 ft-lbs                     1210 fps / 601 ft-lbs

.45 Super 230gr GD JHP                                    1038 fps / 550 ft-lbs                     1025 fps / 536 ft-lbs

*Federal  HST .45 ACP Std P 230gr JHP                779 fps / 309 ft-lbs

*G2 Research  RIP  .45 ACP Std P 162gr JHP        877 fps / 276 ft-lbs

*LeHigh Defense .45 Super 170gr JHP              1100 fps / 456 ft-lbs

*Liberty  Civil Defense .45 ACP +P 78gr JHP        1768 fps / 541 ft-lbs

So, there you can see the general trends pretty well. The standard-pressure .45 ACP loads run about 300 ft-lbs, the +P .45 ACP run up to about 400 ft-pounds, and the .45 Super / .450 SMC rounds are in the 500-600 ft-lbs range. That kind of distribution is what we saw across the board with other barrel lengths, as well (though you’ll have to wait to see the details and caveats on that).

Of course, pure power is just one component for what makes a good ammunition choice. Bullet design & penetration is extremely important when considering a self-defense load. Shootability in your gun is also critical — because if you can’t recover quickly from shot to shot, then you may limit your ability in a stressful situation. Likewise, if the ammo doesn’t function reliably, or damages your gun, that is also a huge factor.

Most of the ammo we tested functioned fairly well in the pair of Bobergs. We experienced FTFs (failure-to-fire) with a number of the different Double-Tap rounds, and not in just the Bobergs. Those seemed to have been due to light strikes on the primer, which could have been due to improper primer seating, ‘hard’ primers, or some other factor. And we ran into some problems with bullet separation with a number of the Buffalo Bore loads, which was confirmed later when I did some additional shooting with those rounds through my Boberg (one of the two used in the testing), to a rate of about one round per magazine. But that is due to the reverse-feed mechanism in the XR45-S, so wouldn’t be a factor in other guns (and indeed wasn’t).

Personally, I find the extra power quite manageable in the Boberg platform, but I am not very recoil sensitive. There also didn’t seem to be any damage caused to the guns by those loads. But I still don’t plan on feeding my gun a steady diet of such hot loads, the same way that I don’t always shoot full-house magnums out of my .357s and .44s. Personal preference.

Look for more results, images, and thoughts in the days to come.

Jim Downey

May 27, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, Boberg Arms, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , | 5 Comments

That’s … unexpected.

Checking this morning’s stats (which I do pretty much every morning, over my first cup of coffee, just out of idle curiosity), I saw that there was an incoming link … from the Washington Post.

???

So I followed the link back, read the article, and didn’t see anything in it about BBTI. However, given the topic of the article (actually, it’s an editorial), I figured that I’d find the incoming link in the comments. And here it is:

enzo11

3/13/2015 3:58 PM CST [Edited]

There are actually many very short barreled pistols ( 7 inch, on down to Derringer-sized under-3 inch) available chambered for the .223 round.

But what this idiot of an author forgets is basic physics : the shorter the barrel, the lower the muzzle velocity. The lower the muzzle velocity, the less penetrating power the bullet has – by a large factor ( the energy is partially determined by the square of the velocity).

For a chart on muzzle velocity for different barrel lengths:

http://www.ballisticsbytheinch.com/223rifle.html

For what that does to the available energy:

http://www.ballisticsbytheinch.com/2011graphs+/223…

 

OK, BBTI wasn’t actually cited by the Washington Post. But it’s still amusing.

 

Jim Downey

March 15, 2015 Posted by | .223, Data, Discussion., Links | , , , , , , , , , | 1 Comment

Upcoming .45 test ammo.

With a little luck in about two months we’ll be doing the formal chop tests of .45 Super, .450 SMC, and some additional .45 ACP loads.  We’ve now got all the ammo on hand, and it’ll be a fun (but tiring) weekend. I thought I would share what actual ammo we will be testing, with the manufacturer’s velocity data:

Buffalo Bore
45acp Low Recoil Std P 185gr FMJ-FN      850fps
45acp Std P 230gr FMJ-RN                    850fps
45acp +P 185gr JHP                      1150fps
45acp +P 230gr JHP                 950fps
45 Super 185gr JHP                1300fps
45 Super 200gr JHP                1200fps
45 Super 230gr FMJ                1100fps
45 Super 230gr JHP                1100fps
45 Super 255gr Hard Cast            1075fps

Double Tap
45acp +P 160gr Barnes TAC-XP        1200fps from 5”     1075fps from 3.5”
450 SMC 185gr JHP                1310fps from 5” 1911
450 SMC 185gr Bonded Defense JHP    1310fps from 5” 1911
450 SMC 230gr Bonded Defense JHP    1135fps from 5” 1911

Hornady
Critical Defense 45acp Std P 185gr FTX    Muzzle 1000fps
Critical Duty 45acp +P 220gr Flexlock    Muzzle 941fps

Underwood
45 Super 170gr CF                1250fps
45 Super 185gr XTP JHP            1300fps
45 Super 230gr GD JHP            1100fps

In addition to the first data for both the .45 Super and .450 SMC cartridges, this will also almost double the number of .45 ACP loads we’ve tested.  We’re looking forward to it!

Jim Downey

March 7, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, Boberg Arms, Data, Discussion. | , , , , , , , , , , , , , , , , | 6 Comments

Boberg XR45-S: experiments in .45 Super loads – part II.

As I mentioned a few days ago, we had another warm spell here which allowed me to get out and test the next round of experimental loads for .45 Super.

As I said last time, before I get into all the nuts & bolts detail of the handloads (which I will do below), let me summarize what I learned for those who aren’t into the geeky stuff. Please note all of this is VERY TENTATIVE, based on this second set of experiments!

  • Going to a tighter crimp pretty much solved the problems I had encountered the first time with bullet separation in the Boberg. This time I only had one partial separation, in a 230gr bullet.
  • Likewise, going to shorter O.A.L. (Over All Length) for most of the loads eliminated most problems I had experienced with feeding.
  • These factors, combined with some different power levels, have put me on the right track to developing a ‘true’ .45 Super load (something which is actually more than just a .45 ACP +P).

To re-iterate: Coming up with a hand load is more art than science, since there are many different factors to consider: type and amount of propellent (gunpowder), weight and profile of the bullet chosen, the overall length (O.A.L.) of the final cartridge because the depth of the bullet seating changes the case capacity and hence the pressure profile, what type and degree of crimping, and the type of primer used.

Here are the numbers, in the same format as last time for easy comparison. Once again, let me note that these are experimental loads, and you choose to use the information here entirely at your own risk, without endorsement from me:

Titegroup powder          Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

6.7gr                          185gr XTP            1.175″                       1050fps                                   970fps

7.3gr                           200gr RNFP          1.250″                       1000fps                                   925fps

6.3gr                           230gr RNFP          1.250″                        950fps                                    900fps

HP-38 powder                Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

7.2gr                          185gr XTP              1.175″                       900fps                                    840fps

7.2gr                           200gr RNFP           1.250″                       900fps                                    830fps

6.8gr                           230gr RNFP           1.250″                       860fps                                    790fps

Longshot powder           Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

10.0gr                         185gr XTP             1.200″                     1100fps                                  1025fps

9.5gr                           200gr RNFP           1.250″                     1010fps                                    910fps

9.0gr                           230gr RNFP           1.250″                     1020fps                                    960fps

 

Curiously, while generally going to a shorter O.A.L. (meaning that the bullet was seated deeper) resulted in the expected increase in velocity, there are a couple of instances where that didn’t happen. I’m not sure how to explain it — could have been an data reporting error on my part (or from the chrono) either this time or last time. Or it could have been not having a large enough sample size. Or it might have some variation in the handloads made for either batch of tests. I just don’t know.

But I’m not going to worry about it overmuch. Now that I seem to have resolved the separation and feeding issues, and seem to be getting good numbers, I am going to build off of these results. That means slight increases in propellant levels so that I surpass published performance numbers for .45 ACP +P. Because of my previous tests, BBTI formal testing, and published numbers for .460 Rowland, I have an upper bound for how the Glock will handle the loads safely and there’s still a lot of leeway before I start pushing those bounds.

One step at a time.

Oh, and I continue to be happy with how the XR45-S is performing. I am still waiting on some “Generation 2” magazine springs, which I think will eliminate the last of the problems I was having with feeding.

 

Jim Downey

January 23, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, .460 Rowland, Boberg Arms, Data, Discussion. | , , , , , , , , , , , , , , , , , , , | 4 Comments

First date with the Boberg XR9-S.

As I noted a couple of weeks ago, I picked up a ‘little brother‘ for my Boberg XR45-S. Here they are again:

Lil brother

Well, we’re having another delightful warm spell here in mid-Missouri, so yesterday afternoon I took advantage of it and went out to the range to give the little guy a try.

As I noted before, I have actually shot this particular gun a couple of times previously, and just loved it. But it had been a while, and I couldn’t remember specifically what ammo types we had used. So I packed up what variety of 9mm loads I had on hand, along with my chrono (which I needed to also do some more testing of .45 Super loads — more on that later), and to see whether anything had changed.

Because of the way they operate, the Boberg pistols have a tendency to be very particular about what ammo they like. Ammo which doesn’t have a sufficient crimp is prone to separate (the case being jerked away from the bullet). It’s an issue which is well known, and there’s a list of compatible ammo for both the XR9 and the XR45. But while those crowd-sourced lists are useful, the final word is always what specific ammo your particular gun will handle. For me, that’s particularly something I want to determine for any self-defense pistol before I will carry it.

Full details to follow, but for those who just want the short version: oh baby! The XR9 ate everything I fed it without a problem. Including my standard 9mm reloads. No mis-feeds. No bullet separation. No problems. And it was a real joy to shoot, which isn’t something I normally say about a pocket pistol handling full-power SD loads.

OK, for those want the details …

Below are informal* chrono numbers for seven different ammo types I had. These are all for the Boberg. But I also ran a few through my Steyr S9 for comparison, which usually just had an advantage of about 10 fps over the Boberg (the barrel on the Steyr is about a quarter of an inch longer). If that much.

  • Buffalo Bore 124gr JHP +P+                                             1,230 fps
  • Federal 124gr Hydra Shok JHP                                           1,025 fps
  • Reloads. (4.4gr HP-38, 124gr Rainier FMJ bullet)                        1,020 fps
  • Remington 124gr FMJ                                                       1,040 fps
  • Speer GDHP 115gr JHP                                                      1,210 fps
  • Speer GDHP 124gr JHP                                                      1,100 fps
  • Speer GDHP 124gr JHP +P ‘Short barrel’                           1,150 fps

As you can see, all pretty respectable numbers. And in keeping with both the claims of the manufacturer as well as what we had tested previously (where there’s overlap). I wouldn’t have any qualms carrying any of the Speer ammo, but my preferred SD ammo is currently the Buffalo Bore. Happily, the Boberg shot all of them without a glitch. And after getting my chrono numbers, I ran several magazines worth through the gun doing some quick shooting at cans, was getting excellent accuracy from it at about 15 yards.

I brought it home, stripped and cleaned it, and now consider it reliable enough to carry. Of course, I will continue to practice with it regularly, and keep a close on on how it performs with my reloads, and occasionally run a mag of carry ammo through it, but I don’t expect any problems. It’s a nice little gun.

 

Jim Downey

*By ‘informal’, I mean just using one chrono and without the lighting rig we now use for formal testing. And I would just run a magazine of ammo through, mentally noting the numbers in a running tally, then writing them down for that particular ammo, so they are necessarily just ‘ballpark’ figures. But since they jibe well with our previous numbers and what the mfg claims (which I only discovered when I sat down to write this), I think they’re pretty good.

 

January 20, 2015 Posted by | 9mm Luger (9x19), Boberg Arms, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , , | 1 Comment

No matter which way you look …

…whether back over 2014, or forward into 2015, things are pretty good vis-a-vis BBTI.

Yeah, 2014 was pretty good. We didn’t do any formal testing, though I did some informal testing and a fair number of reviews of new guns or guns which were just new to me.  Having the chance to do those now and again is enjoyable, without having the same deadline pressures I had when I was doing regular columns and reviews for Guns.com.

The numbers also look pretty good for 2014. This blog went from about 12,000 visits in 2013 to 22,000 last year – nearly double. And the BBTI site itself jumped from 243,230 visitors in 2013 to 318,304 visitors in 2014 — an increase of about a third. Visits have also continued to climb pretty steadily from day-to-day, with typically about 1,250 or so daily by the end of the year. Given that we didn’t do any new testing, that’s pretty impressive.

And of course, we’d like to thank all who linked to us over the past year. Here’s the top ten referring sites for 2014, excluding search engines and Wikipedia:

  1. thefiringline.com
  2. defensivecarry.com
  3. guns.com
  4. thefirearmblog.com
  5. ar15.com
  6. gunsamerica.com
  7. reddit.com
  8. thetruthaboutguns.com
  9. rimfirecentral.com
  10. survivalistboards.com

How about the year to come, then?

Well, we’re planning on doing one largish series of tests, to cover .45 Super, .450 SMC, and a number of additional .45 ACP loadings. We haven’t yet set a date for this sequence, but I will post a note about it here and on our Facebook page once plans solidify.

And behind the scenes, improvements continue at the BBTI website. We recently upgraded our hosting set-up, to shift over to more modern software technology. We’ve started discussing how we can do better presentations of our graphs and spreadsheets. I would still very much like to work with someone to develop a mobile app — if you have the necessary skill set to do that, please drop me a note. And whenever someone finds a glitch in our data or how the site renders for them, we try and make the corrections. None of this is very obvious, but it is all a lot of work, and I’d like to once again thank our web guru (and my lovely wife) at Coeurbois Graphic Design for her efforts.

Lastly, thanks to all who use the site regularly, who cite us in online discussions, who help to spread the word. And especially, I would like to thank all who have donated to BBTI in the last year — your tangible contributions make a difference, and help to offset our ongoing costs.

Happy New Year!

 

Jim Downey

January 2, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, Boberg Arms, Data, Discussion., Links | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment

Boberg XR45-S: experiments in .45 Super loads.

Over the course of the Christmas holiday weekend we had some unseasonably warm and pleasant weather, so I decided to go out to the range and test the first in a series of experimental hand loads I had developed for my new Boberg XR45-S. Since the XR45 is rated for the .45 Super cartridge, these loads were intended to start at about the power level of a .45 ACP+P load to give me a baseline, which I can then build up from there. I wanted to do this because there are actually very limited commercial choices in the .45 Super cartridge, and even less in the way of good testing or reloading data (which is one of the reasons why we’re going to be doing the BBTI chop tests on that cartridge in 2015 as I’ve previously mentioned).

Now, before I get into all the nuts & bolts detail of the handloads (which I will do below), let me summarize what I learned for those who aren’t into the geeky stuff. Please note all of this is VERY TENTATIVE, based on this first set of experiments!

  • The ballistic performance ‘sweet spot’ seems to come in a 200gr bullet loading, in terms of how much loss comes from a shorter barrel (the difference between the 3.75″ XR45 barrel and the 5.0″ Glock 21 barrel I used for comparison.
  • I consistently had problems with not having a tight enough crimp on the rounds at these higher power levels over a lower power standard .45 ACP practice loads. This makes sense because the slide would be moving faster with the higher power loads, leading to more problems with bullet separation.
  • I had problems with a 185gr jacketed hollow point bullet that I didn’t have with either the 200gr or 230gr round-nose bullets. And the problem seemed to be worse with the Hornady XTP JHP bullet than in factory loaded JHPs I have tried. This *might* be due to the increased ‘throat’ size of the XTP in comparison to other brands. Maybe.

Now, about my hand loads. These were all figured based on a variety of sources and my own experience and experiments in creating loads for the .460 Rowland in 2013, since, as noted, there is very little good information readily available for the .45 Super. And while I wanted to try to start at about .45 ACP+P power levels, I wanted to be fairly conservative in doing so, just to be safe. Coming up with a hand load is more art than science, since there are many different factors to consider: type and amount of propellent (gunpowder), weight and profile of the bullet chosen, the overall length (O.A.L.) of the final cartridge because the depth of the bullet seating changes the case capacity and hence the pressure profile, what type and degree of crimping, and the type of primer used. I decided to just use all one type of primer (a fairly standard one) as well as the same amount of light crimp, to help reduce the number of different factors. I also decided to pretty much standardize the O.A.L. though you will see some variation in the Longshot loads. Like I said, it’s more art than science, and you have to start someplace.

Super tests

OK, here’s a table showing the different loads and how they performed. These are experimental loads, and you choose to use the information here entirely at your own risk, without endorsement from me:

Titegroup powder          Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

6.5gr                          185gr XTP            1.175″                         990fps                                     900fps

7.3gr                           200gr RNFP          1.275″                       1100fps                                   1070fps

6.3gr                           230gr RNFP          1.265″                       1020fps                                     970fps

HP-38 powder                Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

6.8gr                          185gr XTP             1.175″                         600fps                                     560fps

8.0gr                           200gr RNFP          1.275″                         920fps                                     850fps

6.8gr                           230gr RNFP          1.265″                         840fps                                     770fps

Longshot powder           Bullet                   O.A.L.*                Glock 21 (5.0″)                Boberg XR45 (3.75″)

10.0gr                         185gr XTP             1.250″                     1020fps                                     960fps

9.0gr                           200gr RNFP           1.250″                     1070fps                                   1010fps

8.0gr                           230gr RNFP           1.275″                       980fps                                     880fps

*O.A.L. = Over All Length

OK, that’s obviously ‘warts & all’, following the same openness that we have done in the formal BBTI tests. I’ve only been back into reloading for about five years, and still have a hell of a lot to learn — as you can see from how badly underpowered the HP-38 loads turned out.

But it’s a decent start. I’m going to spend some more time thinking about the next step, see what additional research and comments suggest (feel free to offer your opinions!). The .45 Super loads available from Buffalo Bore are about 10-20% more powerful than these base loads, so I still have a ways to go in finding the right mix. Given the problems I was having with bullet separation (where the mechanical action of the Boberg causes the case to jerk away from the heavy bullet), the first step is probably to increase my crimp, and see what that does to the velocity (since a strong crimp will cause a greater pressure build-up before the bullet is released). I may also see what seating the bullets deeper does (meaning that the O.A.L. will be less, and again there will be a great pressure spike).

Wish me luck.

Jim Downey

December 27, 2014 Posted by | .45 ACP, .45 Super, .460 Rowland, Boberg Arms, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , | 4 Comments

Six shooter.

Well, well, well, BBTI made it to six years of shooting fun and research!

Yup, six years ago today we posted the first iteration of Ballistics By The Inch, and included data for 13 different handgun cartridges. Since then we’ve continued to expand on that original research, including some extensive testing on how much of an effect the cylinder gap on revolvers has, what performance differences you can expect from polygonal over traditional land & groove rifling, and added another 9 cartridges, as well as going back and including a very large selection of real world guns in all the different cartridges. This blog has had 100,000+ visitors and the BBTI site itself has had something like 25 – 30 million visits (the number is vague because of changes in hosting and record-keeping over time).

We’ve had an impact. I’ve seen incoming links from all around the world, in languages I didn’t even recognize. There’s probably not a single firearms discussion group/blog/site out there which hasn’t mentioned us at some point, and our data is regularly cited in discussions about the trade-offs you make in selecting one cartridge or barrel length over another. I’ve answered countless emails asking about specific points in our data, and have been warmly thanked in return for the work we’ve done. And on more than a few occasions people have pointed out corrections which need to be made, or offered suggestions on how we could improve the site, sometimes providing the results from their own crunching of our data.

When we started, it was fairly unusual to see much solid information on ammo boxes about how the ammunition performed in actual testing. Now that information is common, and expected. Manufacturer websites regularly specify real performance data along with what kind of gun was used for that testing. And the data provided has gotten a lot more … reliable, let’s say. We’ve been contacted by both ammo and firearms manufacturers, who have asked if they can link to our data to support their claims of performance — the answer is always “yes” so long as they make it clear that our data is public and not an endorsement of their product. And we’ve never taken a dime from any of those companies, so we can keep our data unbiased.

And we’re not done. We have specific plans in the works to test at least one more new cartridge (and possibly revisit an old favorite) in 2015. I try to regularly post to the blog additional informal research, as well as sharing some fun shooting and firearms trials/reviews. There’s already been one firearms-related patent issued to a member of the BBTI team, and we’ll likely see several more to come. Because we’re curious guys, and want to share our discoveries and ideas with the world.

So, onward and upward, as the saying goes. Thanks to all who have cited us, written about us, told their friends about us. Thanks to all who have taken the time to write with questions and suggestions. And thanks to all who have donated to help offset the ongoing costs of hosting and testing — it makes a difference, and is appreciated.

 

Jim Downey

November 28, 2014 Posted by | .22, .223, .22WMR, .25 ACP, .30 carbine, .32 ACP, .32 H&R, .327 Federal Magnum, .357 Magnum, .357 SIG, .38 Special, .380 ACP, .40 S&W, .41 Magnum, .44 Magnum, .44 Special, .45 ACP, .45 Colt, .460 Rowland, 10mm, 6.5 Swedish, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures, Links, Shotgun ballistics | , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Perceived recoil and bullet weight.

Got a great question recently, and I thought I would share some of my thoughts about it, then invite others to weigh in. Here’s the question:

I hope that you folks can help me with a question I have had for many years now. Why is the recoil so much heavier with lighter bullets in the same caliber and powder loadings than heavier bullets of the same caliber and loadings?

For example. With my S&W model 60, Gold Dot L/E 38 special 135 grain JHP +P loads recoil much harder than the Remington 125 grain JHP +P loads. The same thing happens with my Glock mod 23 .40cal when I shoot 180 grain JHP rounds vs 165 grain JHP rounds. The 165 grain rounds recoil much harder. One would think the heavier round with the same powder load would recoil harder. Can you help?

Perceived recoil is a surprisingly complex problem. It’s not just a matter of total force, but the ‘shape’ of the recoil impulse as well. Then there are the ergonomics of how a particular gun fits a particular person/hand. Add in the mechanical action of how the gun operates (some use part of the recoil energy to cycle the action, some don’t), and various psychological/physiological factors (are you tired? just had an adrenaline dump? afraid of a given gun/caliber/cartridge?), and you can see how many different factors might come into play.

A good place to start is to look at the equation for Muzzle Energy (ME). Let’s use the numbers for the Steyr M40 (very similar to your Glock 23) which was one of the ‘real world’ guns used in the .40 S&W tests we did. Calculations are from Airhog.

The 165gr Federal Hydra-Shok JHP has a velocity of 943fps out of the 4″ barrel. That gives a Muzzle Energy of 325.88ft-lbs.
The 180gr Federal Hydra-Shok JHP has a velocity of 989fps out of the 4″ barrel. That gives a Muzzle Energy of 391.04ft-lbs.

OK, that would seem to indicate that the heavier bullet should cause more recoil. The ME is higher, and you’re shooting them out of the same gun.

But I’m a little wary of that example. Usually, a lighter bullet is faster than a heavier one if they have the similar powder charge, out of barrels of the same length. Here’s another example, looking at 9mm from a Beretta 92.

The Cor-Bon 90gr JHP +P has a velocity of 1522 out of the 4.875″ barrel. That gives a Muzzle Energy of 463.05ft-lbs.
The Cor-Bon 125gr JHP +P has a velocity of 1291 out of the 4.875″ barrel. That gives a Muzzle Energy of 462.72ft-lbs.

And those are very close to the same amount of ME, and should feel about the same in terms of recoil were that the only factor.

So what’s going on? Why do we see one instance where the ammo is just a bit faster in the heavier bullet (resulting in higher ME), but much slower in another instance?

I suspect that it’s probably due to differences in loadings between the different ammo. Even with ammo from the same manufacturer (in the examples above), there’s nothing saying that they are using either the same propellant OR similar amounts of the same propellant for loadings which use different bullet weights. That means that trying to generalize the amount of recoil between different bullet weights just on the basis of brand is difficult if not impossible.

Furthermore, if you’ve done any reloading, or spend some time looking over reloading data, you’ll know that even when you’re using the same propellant in the same cases, different bullet weights usually means different bullets (in terms of manufacturer and/or shape) resulting in different seating depths and overall length. It may seem to be a trivial matter, but this results in different pressure profiles (the amount of pressure within the firing chamber of the gun). Just one example, taken from the Hodgdon Reloading site, for maximum-pressure loads using  GDHPs:

The 90gr bullet with 7.0gr of Longshot powder has an overall length of 1.010″ and gives a velocity of 1,378fps, a pressure of 32,300 PSI, and would have a ME of 379.57ft-lbs.
The 115gr bullet with 6.0gr of Longshot powder has an overall length of
1.125″ and gives a velocity of 1,203fps, a pressure of 32,300 PSI and would have a ME of 369.64ft-lbs.

Note that while the heavier bullet uses a full 1.0gr less of propellant and has a longer overall length, it generates the same amount of pressure. If we drop back to the same amount of the same powder for each loading (6.0gr), then the pressure generated in the lighter bullet loading drops to 29,400 PSI, velocity drops to 1,278fps, and ME drops to 326.48ft-lbs.

But not all pressure is created equal, even if it is nominally ‘the same’. The pressure impulse also matters. That’s the curve of how the pressure rises and falls over time, which is largely related to how ‘fast’ or ‘slow’ the propellant burns. Propellants used for handgun loads tend to be very ‘fast’ (burn rapidly), so the impulse tends to be sharper.  Here’s a good explanation of the matter.

And if you think about it, the heavier the bullet used, the longer/slower it takes to start moving when the cartridge is fired. That should mean that the impulse is spread out over a slightly longer time than it would be with a lighter bullet. So in some sense, the lighter bullet would result with a ‘snappier’ feel. And that may well be what it is that you’re feeling when you experience more perceived recoil (and have controlled for all the other factors) from lighter bullets.

Other thoughts on the subject?

 

Jim Downey

 

 

 

 

June 15, 2014 Posted by | .38 Special, .40 S&W, 9mm Luger (9x19), Data, Discussion., Links | , , , , , , , , , , , , , , , | Leave a comment

Questions, we get questions …

I thought I would share a question I got in email today, and my generalized answer, since it is something which comes up surprisingly often.

 

I love this data! Would it be possible to fund the testing of additional cartridges?  I’m looking for more .XYZ load tests.

Our baseline costs for testing a particular cartridge (out to 18″ barrel length) runs a couple hundred dollars for the barrel blank, then perhaps another hundred to get the smithing work done on it to fit the T/C platform. Then add in the actual cost of ammo, with a minimum of probably 100 rounds (3 shots at each inch of barrel, additional rounds for each ‘real world gun’, and then another box or two for repeats when something goes buggy with the data). So realistically, to actually fund a test sequence is a minimum of close to $500 for just one ammo load, and another $100+ for each additional ammo. Add in equipment and site hosting costs, and that’s how we’ve managed to spend something on the order of $50k so far for the data on the site. Which doesn’t include any labor costs, of course, since we only do this because we were curious about the data, not as any kind of testing business.

Which is to say that we’re always happy to accept donations and feedback on what sorts of things people would like to see, but as of yet no one has been willing to step up and finance an entire test sequence for something we’re curious enough to want to sink the time into. (Each test sequence takes 100 man-hours of labor or more … from our vacation/weekend/fun time.)

We don’t *currently* have any plans to retest the .XYZ anytime soon. Actually, we don’t have plans to do any specific tests at all in the near term. But we are looking at revisiting most or all of the cartridges tested to date at some point in the future, just to see how ammo quality/selection may have changed over a 5 or 10 year period.

 

Jim Downey

June 5, 2014 Posted by | Anecdotes, Data, Discussion., General Procedures | , , , , , , , , , | Leave a comment

Confirmation of the .460 Rowland performance.

John Ervin at Brass Fetcher Ballistic Testing has just put up a new page about his testing of the .460 Rowland cartridge. As I have explained in the past,  our work at BBTI is intended to be an overview of how ballistic performance varies over barrel length — it is just a quick survey to get an idea of the general trends, not meant to be an in-depth examination of a specific cartridge.

But in-depth testing is exactly what Ervin does, using a larger sample size, ballistic gelatin, and high-speed videography. And as a result, his much more detailed analysis is more useful for getting into the details of a given cartridge out of a specific barrel length. And it is really good to see that his results confirm what I have been saying all along: that if you carry a .45, you should instead be carrying a .460 Rowland.

What specifics? Take a look at the performance of Speer 230gr Gold Dot HP .45ACP in terms of foot-pounds of kinetic energy transfer into 20% ballistic gel:

 

Pretty good, eh? It’s what we expect from the .45ACP: a solid energy dump and reasonable penetration.

Now let’s take a look at the same chart, but with the Speer 230gr Gold Dot HP in .460Rowland:

The curves don’t look that different on first glance, but pay close attention to the scale there on the left axis of each one: where the .45ACP tops out at about 72 ft/lbs about 2″ into the gel, the .460Rowland tops out at about 335 ft/lbs just before 2″. That’s more than 4x the energy transfer.

In fact, at 5″ of penetration, the .460Rowland is still dumping about as much energy as the .45ACP does at the maximum.

But there’s more than simple energy transfer involved in terminal ballistic performance. There’s also how well the bullet is designed, and whether it expands properly. This can be a big concern in “over-driving” a bullet, so that it breaks apart. Well, Ervin’s data also covers these comparisons quite well. For the two specific rounds cited above, the .45ACP expanded to 0.344 square inches of frontal surface, and was still 229.5gr of weight. And the .460Rowland expanded to 0.526 square inches of frontal surface, and was still 221.3gr of weight.

There’s a *LOT* more information at Brass Fetcher Ballistic Testing. Ervin has an extensive 17 page Ammunition Performance Data report in .pdf format which contains a ton of images, video, and data — more than enough to keep even a data-junkie like me busy for a long time. I urge you to take a good look at it, and to consider the thoughts which Ervin shares about this cartridge. But I will leave you with his opening sentence which sums it up very nicely:

The 460 Rowland represents the pinnacle of handgun calibers for self-defense.

 

Agreed.

Jim Downey

May 1, 2014 Posted by | .45 ACP, .460 Rowland, Data, Discussion., Links | , , , , , , , , , , , , , , , , , | Leave a comment

.460 Rowland case wall thickness.

A friend dropped me a note, after looking over my previous experiments with putting .460 Rowland load power into .45 ACP cases, and asked a fairly simple question: Do you think that the case walls are actually thicker in the .460 Rowland?

Now, I have read several articles over the years which mentioned that the .460 Rowland cases were “stronger” with others saying that the cases were “thicker”. In fact, in the blog post cited above, I myself said:

Even shooting them in a gun designed to handle .460 Rowland power was risky, since the .45 ACP cases do not have the same strength as the .460 Rowland cases.

But is that actually true?

Good question. My Lyman 49th Edition Reloading Handbook doesn’t give case wall thickness for the .45ACP, and doesn’t list .460 Rowland at all. A quick check online also didn’t turn up any case wall thickness specs for either cartridge. As noted above, there are some gun writers out there who claim that the .460 Rowland case has thicker walls “for strength” but this claim isn’t made on the 460Rowland.com site that I could find.

So, being the data-curious guy that I am, I decided to just take some measurements and see what I found.

The only .460 cases I have are all Starline brass (I ordered 500 from them, and supplemented with other brass from factory Buffalo Bore ammunition – again, all of it marked as Starline), and I went through and checked a bunch with my simple calipers. Now, those calipers aren’t the pincer type, just the standard parallel-jaws type, so I only trust the measurements to about halfway down the case. And they all fell into a range of wall thickness from 0.0012″ to 0.0014″.

Doing the same measurement with ten different ‘marked’ sets of .45 ACP brass I also have readily to hand, the results were almost identical, with the vast majority of cases being 0.0012″ or a thousandth of an inch on either side of that. It didn’t matter whether the cases were nickle-plated or marked “+P”. The ‘marked’ brass was as follows:

  • Cor Bon +P
  • ELD
  • Federal Brass
  • Federal Nickle
  • R-P
  • S&B
  • Speer Brass
  • Speer Nickle
  • Starline
  • Winchester

And when you stop to think about it, there would be no reason or way for the case walls to be significantly thicker in the .460 Rowland cartridge, and still allow you to use standard .45 ACP reloading components and dies. If the case walls were substantially thicker, then you’d have to have slightly smaller bullets, if nothing else, and would probably need a different resizing die and/or neck expanding die.

Also, when I was conducting those experiments last summer, I didn’t note any differences in how the .45 ACP cases looked or functioned (when being reloaded) after being shot with .460 Rowland power loads.

My conclusion? That the .460 Rowland cases are no thicker walled than .45 ACP cases. They may still be “stronger”, if there is some metallurgical difference, but I doubt it. The real difference is in whether or not the chamber of the gun in which the ammo is being used is strong enough to handle the much-greater pressure of the .460 Rowland loads. Because remember, the maximum pressure for standard .45 ACP is just 21,000 PSI, and 23,000 PSI for .45 ACP +P — while the .460 Rowland cartridge reaches pressures of 40,000 PSI.

Of course, there are additional factors to consider (like recoil and timing) with the .460 Rowland cartridge, so you can’t just make the chamber of the gun stronger and then start putting those kinds of loads into .45 ACP cases. And you really wouldn’t want to accidentally put such power into a ‘normal’ .45 ACP gun — that could lead to catastrophic failure of the gun, and result in serious injury or death. So it still makes ALL KINDS OF SENSE to only load the longer .460 Rowland cases with that much power.

 

Jim Downey

March 22, 2014 Posted by | .45 ACP, .460 Rowland, Anecdotes, Data, Discussion. | , , , , , , , , , , , | 4 Comments

Wait … it’s 2014?? How did THAT happen?

2013 was a busy year for BBTI.

We did the .22Mag tests. We did the 9mm Glock Tests. I got my .460 Rowland conversion up and running. And I found some really fun .44Mag +P+ loads, then figured out a simple hack so that they would feed reliably in my lever gun. Like I said, a busy year.

And we couldn’t have done it without help. Of several types. To see the list of those donors who have helped offset some of our operating costs, pop over to the BBTI site. And here’s a list of the top-10 referring sites (excluding search engines and Wikipedia):

  1. thefiringline.com
  2. defensivecarry.com
  3. guns.com
  4. thefirearmblog.com
  5. ar15.com
  6. thetruthaboutguns.com
  7. survivalistboards.com
  8. glocktalk.com
  9. reddit.com
  10. rimfirecentral.com

Altogether, we had 243,230 visitors to the BBTI website, and some 12,000+ views of this blog. Since we’ve gone through several iterations of the site over the last five years, it’s hard to say exactly how many visitors or pageviews or hits we’ve had in total — but it’s more than we ever really expected. Thanks, everyone.

And particular thanks to my Good Lady Wife, who has done all the webwork and most of the number crunching over the years.

We don’t currently have any concrete plans for new tests in 2014. But who knows? Keep an eye here and on our Facebook page for news.

Happy New Year, everyone!

 

Jim Downey

 

January 1, 2014 Posted by | .22WMR, .44 Magnum, .460 Rowland, 9mm Luger (9x19), Anecdotes, Data, Discussion., Links | , , , , , , , , , , , , , , , , , | 3 Comments

Some Muzzle Energy comparisons.

I got a nice note from Jason at Leaf Technologies, who had been curious about how different cartridges compared in terms of Muzzle Energy (ME). So what he did was take the data from BBTI and average the ME curves for the cartridges he was interested in, then plot them head-to-head in one Excel graph. He sent me the result, and with his permission I am sharing it here:

MEgraph

(Click to enlarge.)

I always love to see how others use our data, and the conclusions they draw from it. It’s EXACTLY the sort of thing we hoped would happen, and why we’ve made the data freely available. If you would like to read some of Jason’s conclusions, and the discussion they engender, pop over to the Northeast Shooters Forum.

And if you have your own interesting spin on how our data can be used in a new way, drop me a note. If I think it’d be of interest to others, I’ll be happy to post it here/link to it. Just send an email to jimd@ballisticsbytheinch.com

 

Jim Downey

December 12, 2013 Posted by | .357 Magnum, .357 SIG, .380 ACP, .40 S&W, .45 ACP, 10mm, 9mm Luger (9x19), Data, Discussion., Links | 1 Comment

Happy Thanksgivuk … er, I mean Birthday!

OK, first: Happy Thanksgiving to all my fellow Americans. And Happy Hanukkah to all who observe it!

But most of all,

Happy Birthday to BBTI!

Yeah, it’s our fifth birthday. We officially launched the site on Thanksgiving in 2008.  And it’s been a fun romp since then. We’ve gone through many different iterations on the site, adding in more calibers/cartridges, doing the big cylinder gap test, tweaking this and changing that. We’ve shot something on the order of 22,000 – 23,000 rounds. We’ve had something in excess of 20 million hits to the site. We’ve invested more than $50,000 and untold hundreds of hours of labor. And we’ve become pretty much the default resource for anyone who has needed (or just wondered about) data pertaining to handgun ammunition performance over barrel length. Like I said, it’s been fun! Thanks for helping to make it so!

And since it is our birthday, it’s time for a gift in the form of a whole new section to the BBTI website:

Polygonal v. Traditional L&G Rifling (“Glock tests”)

From that page:

For years people have wondered about the effects of the different styles of rifling, and whether one or the other would offer specific advantages for accuracy or velocity from a given cartridge.  But since many different factors can have an effect on both accuracy and velocity, these discussions have largely remained anecdotal.  We decided to see whether we could generate data as to performance differences between the two styles of rifling as concerns bullet velocity, using our standard chop-test techniques.  The data on this page is the result of those tests.

Check it out when you get a chance! And thanks again to all who have shared links to our site, who have sent us emails, who have contributed to help offset our costs — you folks have made our success possible, and it is very much appreciated.

 

Jim Downey

PS: as a personal thanks as well, I have made both my first novel and our care-giving memoir available for free download for today and tomorrow (Nov. 28th & 29th).

November 28, 2013 Posted by | 9mm Luger (9x19), Anecdotes, Data, Discussion., Links | , , , , , , , , , , , , , , , , , | 1 Comment

Follow

Get every new post delivered to your Inbox.