ATTENTION:  Effective Sept 1, 2020, the BBTI Project is in "Archive Status."  No further tests will be conducted, but we will maintain this site and data for the use of the firearms community.  Thank you.

Scope of the Project

Initially we decided to test thirteen common pistol calibers/cartridges (subsequent testing expanded this to twenty-two different calibers/cartridges), each over a range of barrel lengths from 18" down to 2", and each using a variety of ammunition (most of it "premium" ammo made for self-defense purposes).  In each case we fired three rounds of a given ammo at a given barrel length, recording the velocity of the bullets at 15 feet with two commercial chronographs.  If we did not get two reliable readings for each of three rounds, we repeated the process until we did.  Altogether we have fired about 20,000 rounds of ammunition.

In order to get consistent results, we opted to use a platform which would accommodate barrels of any caliber - a Thompson/Center Encore No. 1842.  A gunsmith was commissioned to create 11 barrels (calibers tested such as .38 special/.357 magnum used only one barrel) which would each fit into a single housing, yet allow us to chop the barrels easily.  This means that we could directly compare calibers regardless of mechanical issues (such as whether there was energy loss due to a cylinder gap or activating an extractor) and as such constitutes an 'ideal' performance.

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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.

We have also tested a number of personal firearms (both handguns and carbines) using the same ammunition as used with the T/C Encore, in order to give some benchmark comparisons between the 'ideal' and the 'real world' performance of a given ammo at a given barrel length.  The same protocols were followed, and we used the same ammo.

Other Resources

BBTI is not the end-all of ballistics testing, just one more component available for the common good.  In addition to extensive discussion about ballistics to be found at many gun forums, here are some other great resources pertaining to ballistics testing you should check out.  (And if you would like to recommend a site to list here, please send an email.)
  • BrassFetcher:  excellent resource, with an emphasis on bullet performance in ballistic gelatin
  • The Box O' Truth:  testing ammo penetration through various barriers
  • Terminal Ballistics Research:  Specializes in the research of cartridge & projectile performance, using hard data gathered from 20 years of hunting game.


We'd like to personally and specifically thank Pat Childs at Fin & Feather in Iowa City, as he not only helped get most of our ammunition and other supplies, he was the brilliant gunsmith who worked with us to make this insane project much more practical.  Without his help all of this would have been much more difficult and perhaps impossible.  Anyone who uses our data owes him a debt of gratitude.

And thanks to our spouses, who were not just tolerant but enthusiastically supportive of this rather nutty project.


This project, and all of its results, is only our fault.  We (well, Jim K, mostly) paid for everything ourselves, and we did not receive any kind of sponsorship or remuneration from anyone.  We did all the work.  We used products we were either familiar with, or because they were what was available, and mentioning them by name does not constitute an endorsement of any kind.  Furthermore, the data is provided purely for entertainment purposes - to better facilitate arguments over what ammo or caliber or gun is "best."  How you use the data is entirely up to you.  And if you think you could do better, feel free to spend the money and do the work and publish your own results.  Or not.  Your choice.