I was excited to hear from Jim that Ballistics By The Inch will soon be testing how much a revolvers’ cylinder gap effects the ballistic performance of a round.

We’ve had a Single Action Army clone in .357 magnum modified to allow for adjusting the barrel position from a standard 0.006″ to 0.001″ to no gap (barrel snug against the cylinder). We have a dozen or so different ammunition loads in .38/.357, and we’ll be essentially repeating the BBTI procedure for each of these, with the normal gap then the minimum gap then without any gap, starting with an 18″ barrel and going down in increments of one inch to just 1″ . Actually, one slight difference – to make sure we get a better statistical sample, we’ll be firing 10 (ten) rounds of each type of ammunition at each point rather than just 3 (three) as we did with the BBTI tests. Because we are limiting this test to just one caliber, we thought this was a reasonable step to take. We hope that this will allow us to conclude with some actual data what the effect of having a cylinder gap in a revolver actually amounts to.

These tests are sure to settle a few arguments.