Ballistics by the inch

Join the party.

All along, we’ve said that if someone wanted to take the time, trouble, and expense to do some additional research along the lines of our protocols, that we’d be happy to include their data on our site. This is particularly true if it helped expand the selection of “real world guns” associated with the data for a given caliber/cartridge. Well, for the first time someone has expressed an interest in doing just that, prompting us to come up with an outline of what standards we feel are required for making sure it relates to our previous tests.

The biggest problem is that ammo manufacturers may, and do, change the performance of their products from time to time. This is why we have on occasion revisited certain cartridges, doing full formal chop tests in order to check how specific lines of ammo have changed. That gives us a benchmark to compare other ammo after a period of several years have passed, and shows how new tests relate to the old data.

But without going to such an extent, how can we be reasonably sure that new data collected by others using their own firearms is useful in comparison to our published data?

After some discussion, we feel that so long as any new testing includes three or more of the specific types of ammo (same manufacturer, same bullet weight & design) we had tested previously, then that will give enough of a benchmark for fair comparison. (Obviously, in instances where we didn’t test that many different types of ammo in a given cartridge, adjustments would need to be made). With that in mind, here are the protocols we would require in order to include new data on our site (with full credit to the persons conducting the tests, of course):

  1. Full description and images of the test platform (firearm) used in the tests. This must specify the make, model number, barrel length, and condition of the firearm. Ideally, it will also include the age of the firearm.
  2. That a good commercial chronograph be used. Brand isn’t critical — there seems to be sufficient consistency between different models that this isn’t a concern. However, the brand and model should be noted.
  3. Chronographs must be positioned approximately 15 feet in front of the muzzle of the firearm used to test the ammo. This is what we started with in our tests, and have maintained as our standard through all the tests.
  4. That five or six data points be collected for each type of ammo tested. This can be done the way we did it, shooting three shots through two different chronographs, or by shooting six shots through one chronograph.
  5. All data must be documented with images of the raw data sheets. Feel free to use the same template we used in our tests, or come up with your own.
  6. Images of each actual box of ammo used in the test must be provided, which show the brand, caliber/cartridge, and bullet weight. Also including manufacturer’s lot number would be preferred, but isn’t always possible.
  7. A note about weather conditions at the time of the test and approximate elevation of the test site above sea level should be included.

We hope that this will allow others to help contribute to our published data, while still maintaining confidence in the *value* of that data. Please, if you are interested in conducting your own tests, contact us in advance just so we can go over any questions.


Jim Downey

September 9, 2016 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, .45 Super, .450 SMC, .460 Rowland, 10mm, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

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 | , , , , , , , , , , , , , , , , , , , , , | 1 Comment

It’s Up!

The new Ballistics By The Inch site is now up and running! Bigger, Faster, And with More DATA! Take a look, spread the word, let us know if there are any glitches or problems.

Jim Downey

December 1, 2011 Posted by | .22, .223, .25 ACP, .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, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures, Links | , , , , | Leave a comment

Wiki, oh Wiki, where do you roam?

Just spent a chunk of the afternoon and early evening doing something I had been meaning to do for at least a year: adding info about BBTI to various and sundry Wikipedia pages about ballistics and cartridges. I still need to create an actual ‘page’ about BBTI, but haven’t ever done that, so . . .

Anyway, now for all the cartridges/calibers we tested there are links on Wikipedia, plus any related entries that I could think of. But if you find yourself poking around there, and come across an entry which would appropriately link/mention BBTI, please edit it to do so (or drop me a note and I’ll take care of it.) This isn’t an effort to get more hits to the BBTI site (we’re rapidly approaching 2.5 million), but just to help more people get the information that they need.

Jim Downey

April 30, 2010 Posted by | .25 ACP, .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, 10mm, 9mm Luger (9x19), Data, Discussion., Links, Uncategorized | 2 Comments

Closing in on a million.

Just under a month ago I wrote about launching the major upgrade to BBTI. Since then, we’ve had 217,390 hits to the site, bringing us to just shy of one million hits (986,999) as of midnight. Given how things have been going the last couple of days, I expect we’ll break a million today or tomorrow. [edited to add: we had over 21 thousand hits on 6/27, thereby crossing a million.]

And that’s kinda cool.

So, thanks to all who passed along word of our project. In particularly, our top ten referrers have been:


I find it interesting that the top referrer (by a long shot) isn’t even a firearms-related site. That we’ve risen high in Google searches comes as very little surprise, and I’m pleased that the BBTI blog itself has such a prominent spot, just after five of the best known gun forums/blogs. That’s kinda cool, too.

Anyway, thought I would pass this bit of good news along.

Jim Downey

(Cross posted to my personal blog.)

June 27, 2009 Posted by | .25 ACP, .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, 10mm, 9mm Luger (9x19), Data, Links | 1 Comment

Six months ago.

Six months ago we launched Ballistics By The Inch. And since then we’ve had over 770,000 hits, one major magazine article, and coverage & discussion of the site in countless gun forums & blogs around the globe. When I have checked the stats for the site, I have never failed to be impressed with just how widely it has become known.

Well, tonight we posted a major upgrade to the whole site. This includes three additional caliber ‘chop tests’, but it also includes data collected from testing over 40 additional “real world” guns – including a baker’s dozen carbine-length guns. This data has been separated out into a new series of graphs for easy comparison. All together, there are now over 150 graphs showing ballistic performance – along with all the charts giving numerical averages for each 1″ increment in barrel length for 16 different calibers. And for the true data junkies, there are downloadable files (in two formats) for the entire sequence of initial tests, and another set for the second round of testing done in April 2009.

Like the initial project, this major upgrade and revision has been a huge job – and one only made possible by a lot of work from several individuals. Yes, there were the three of us testers from the original project. But there was also the addition of a fourth tester this time around who helped us gather & operate all those ‘real world’ guns, and I would like to welcome Keith to our team. But I would especially like to thank my good lady wife for all the html coding & design for our website – both the last time and with this major revision. Quite literally, none of this would have been available without her hard work.

There will probably be minor tweaks and additions to the site in the coming months and years. We still have some ideas of data which might be of interest to the gun community. But for now we hope that you will enjoy and make use of the data provided, and help to spread the word to others who may be interested.


Jim Downey

(Cross posted to my personal blog.)

May 28, 2009 Posted by | .25 ACP, .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, 10mm, 9mm Luger (9x19), Data | 3 Comments

That interesting .32/.327 caliber…

I came across an interesting discussion of the .32 H&R over on TFL, and added these comments:

I’m intrigued by the caliber, as well. We’d tested the H&R Mag in our first series of tests, and just recently completed doing the .327 Mag tests (data should be available on our site in 10 days – 2 weeks). I had been very skeptical about the .327 but the tests were impressive.


Hammer It, I’m not at all surprised by those numbers. I just pulled the data sheets from our chop tests for the .327 Mag and they are all in excess of what you got. We tested the following ammo: Federal Hydra-Shok 85 gr, American Eagle 100 gr JSP, and Speer GDHP 115 gr. At the full 18″ barrel the velocities we got were all in excess of 1900 fps (with the AE almost 2200 fps). At 6″ all were in the 1700 fps range, at 4″ they were 1450 – 1600 fps. And, as noted on our site:

One note: in every case with the T/C Encore the length of the barrel was measured from the end of the barrel back to the breech face. This is how semi-auto pistols are measured, but revolvers are measured as the length of the barrel in front of the cylinder gap. Take this into consideration when comparing calibers using our numbers.

So the numbers for a revolver with a 2″ barrel would fall approximately in that 4″ chop test range.

Yeah, I am very intrigued by the .327 magnum. Certainly, you’re not going to get the same kind of performance as you would with a .357 magnum throwing a heavier bullet at similar velocities, but the 115 gr slug is considered a good 9mm round – and those velocities for the .327 are significantly higher.


Jim Downey

May 3, 2009 Posted by | .32 H&R, .327 Federal Magnum, 9mm Luger (9x19), Anecdotes, Data, Discussion. | Leave a comment

.32 H&R

Here is a post pertaining to the testing and results obtained for the .32 H&R caliber.

November 26, 2008 Posted by | .32 H&R | 2 Comments