Ballistics by the inch

Velocity is great, but mass penetrates.

OK, kiddies, it’s time for SCIENCE!

Ballistic science, specifically. I promise to keep the math to a minimum, because I don’t like it much, either. Jim Kasper is the one who thinks in terms of equations, not me.

If you look at any of the various pages for test results on BBTI you will see that each caliber/cartridge also has a link for a Muzzle Energy (the kinetic energy of a bullet as it leaves the muzzle of a gun) graph for that set of results. That’s because Muzzle Energy can also give an idea of the effectiveness of a given ammo, since it is a calculation of both the weight of a bullet as well as the velocity it is traveling. This calculation, specifically:

E_\text{k} =\tfrac{1}{2} mv^2

Here’s what that says in English, taken from the explanation that goes with that image on Wikipedia:

The kinetic energy is equal to 1/2 the product of the mass and the square of the speed.

In other words, you multiply the weight of the bullet times the square of the velocity, then take half of whatever number you get. And that gives you the Muzzle Energy, usually (as on our site) expressed in foot-pounds of energy.

So there are two ways you can change the result: change the amount of weight, or change the amount of velocity.

But since it is the square of the velocity (the velocity times itself), changes to the velocity have a larger impact on the final amount of Muzzle Energy. That’s the reason why how the velocity changes due to barrel length is such a big deal, and why we’ve done all the research that we’ve done over the last seven years.

But while Muzzle Energy gives you a good way to compare the power and potential effectiveness of a given cartridge as a self-defense round, there are a couple of other factors to consider. A couple of VERY important factors.

One is the shape and composition of the bullet itself. There’s a very good (surprisingly good, in fact — I heartily recommend you read the whole thing) discussion of the basic shapes and how they interact with the human body in this online teaching tool intended for medical students. The relevant excerpt:

Designing a bullet for efficient transfer of energy to a particular target is not straightforward, for targets differ. To penetrate the thick hide and tough bone of an elephant, the bullet must be pointed, of small diameter, and durable enough to resist disintegration. However, such a bullet would penetrate most human tissues like a spear, doing little more damage than a knife wound. A bullet designed to damage human tissues would need some sort of “brakes” so that all the KE was transmitted to the target.

It is easier to design features that aid deceleration of a larger, slower moving bullet in tissues than a small, high velocity bullet. Such measures include shape modifications like round (round nose), flattened (wadcutter), or cupped (hollowpoint) bullet nose. Round nose bullets provide the least braking, are usually jacketed, and are useful mostly in low velocity handguns. The wadcutter design provides the most braking from shape alone, is not jacketed, and is used in low velocity handguns (often for target practice). A semi-wadcutter design is intermediate between the round nose and wadcutter and is useful at medium velocity. Hollowpoint bullet design facilitates turning the bullet “inside out” and flattening the front, referred to as “expansion.” Expansion reliably occurs only at velocities exceeding 1200 fps, so is suited only to the highest velocity handguns.

Now, while that last bit about needing to exceed 1200 fps may have been true, or a ‘good enough’ approximation a few years ago, it isn’t entirely true today. There has been a significant improvement in bullet design in the last two decades (and these innovations continue at a rapid pace), so that there are now plenty of handgun loads available which will reliably expand as intended in the velocity range expected from the round.

The other REALLY important consideration in bullet effectiveness is penetration. This is so important, in fact, that it is the major criteria used by the FBI and others in assessing performance. From Wikipedia:

According to Dr. Martin Fackler and the International Wound Ballistics Association (IWBA), between 12.5 and 14 inches (318 and 356 mm) of penetration in calibrated tissue simulant is optimal performance for a bullet which is meant to be used defensively, against a human adversary. They also believe that penetration is one of the most important factors when choosing a bullet (and that the number one factor is shot placement). If the bullet penetrates less than their guidelines, it is inadequate, and if it penetrates more, it is still satisfactory though not optimal. The FBI’s penetration requirement is very similar at 12 to 18 inches (305 to 457 mm).

A penetration depth of 12.5 to 14 inches (318 and 356 mm) may seem excessive, but a bullet sheds velocity—and crushes a narrower hole—as it penetrates deeper, while losing velocity, so the bullet might be crushing a very small amount of tissue (simulating an “ice pick” injury) during its last two or three inches of travel, giving only between 9.5 and 12 inches of effective wide-area penetration.

As noted above, the design of the bullet can have a substantial effect on how well it penetrates. But another big factor is the weight, or mass, of the bullet relative to its cross-section — this is called ‘sectional density‘. Simply put, a bullet with a large cross-section and high mass will penetrate more than a bullet with the same cross-section but low mass moving at the same speed. It isn’t penetration, but think of how hard a baseball hits versus a whiffleball moving at the same speed. They’re basically the same size, but the mass is what makes a big difference. (See also ‘ballistic coefficient‘).

With me so far?

OK, let’s go all the way back up to the top where I discussed Muzzle Energy. See the equation? Right. Let’s use the baseball/whiffleball analogy again. Let’s say that the baseball weighs 5.0 ounces, which is 2,187.5 grains. And the whiffleball weighs 2/3 of an ounce, or 291.8 grains. A pitcher can throw either ball at say 60 mph, which is 88 fps. That means (using this calculator) that the Kinetic Energy of a baseball when it leaves the pitcher’s hand is  37 foot-pounds, and the whiffleball is just 5 foot-pounds. Got that?

But let’s say that because it is so light, the pitcher can throw the wiffleball twice as fast as he can throw a baseball. That now boosts the Kinetic Energy of the whiffleball to 20 foot-pounds.

And if you triple the velocity of the whiffleball? That gives it a Kinetic Energy of 45 foot-pounds. Yeah, more than the baseball traveling at 88 fps.

OK then.

Now let’s go look at our most recent .45 ACP tests. And in particular, the Muzzle Energy graph for those tests:

What is the top line on that graph? Yeah, Liberty Civil Defense +P 78 gr JHP.  It has almost 861 foot-pounds of energy, which is more than any other round included in those tests. By the Muzzle Energy measure, this is clearly the superior round.

But would it penetrate enough?

Maybe. Brass Fetcher doesn’t list the Liberty Civil Defense +P 78 gr JHP. But they did test a 90 gr RBCD round, which penetrated to 12.0″ and only expanded by 0.269 square inch. Compare that to the other bullets listed on his page, and you’ll see that while the depth of penetration isn’t too bad when compared to other, heavier, bullets, that round is tied with one other for the least amount of expansion.

Driving a lightweight bullet much, much faster makes the Muzzle Energy look very impressive. Just the velocity of the Liberty Civil Defense +P 78 gr JHP is impressive — 1865 fps out of a 5″ barrel is at least 50% faster than any other round on our test results page, and almost 400 fps faster than even the hottest of the .45 Super loads tested.

But how well would it actually penetrate? Without formally testing it, we can’t say for sure. But I am skeptical. I’m not going to volunteer to getting shot with one of the things (or even hit with a whiffleball traveling 180 mph), but I’m also not going to rely on it to work as it has to in the real world, where deep penetration is critical. I want a bullet with enough punch to get through a light barrier, if necessary. Like this video from Hickok45, via The Firearm Blog:

Personally, I prefer a heavier bullet. Ideally, I want one which is also going to have a fair amount of velocity behind it (which is why I have adapted my .45s to handle the .45 Super). All things being equal (sectional density, bullet configuration and composition), velocity is great, but mass is what penetrates.

Jim Downey

November 8, 2015 Posted by | .45 ACP, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 Comments

Some “Super” performance out of a Cx4 Storm.

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 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 | , , , , , , , , , , , , , , , , , , , , , , , , , | 12 Comments

Ammo test results for a pair of 1911s

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.

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, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 Comments

Ammo test results in two versions of the Glock 21

This is the first in a series of informal blog posts about the .45 ACP/Super/.450 SMC testing sequence we conducted over the Memorial Day weekend.

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

getting set

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 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

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. 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 | , , , , , , , , , , , , , , , , , , , , , , , , | 6 Comments