I remember one time long ago when I shot somebody’s Beretta with spectacular accuracy. I could never replicate that load in any of my pistols. I tried different combinations using different components, as well as new and reloaded brass. I did seating depth tests, which do influence group size, but could never get the gun to cloverleaf like my rifles do. I realize that I am a variable and a ransom rest would probably cut my groups in half, but after watching their YouTube videos I’m not so sure.
After manipulating all the commonly known variables with unacceptable results I thunk the following:
Bullet Setback during feeding into the chamber will change the coal and raise pressures, also change velocity, and accuracy. Obviously. So I measured bullet setback. Using new Starline brass, expanded with a Redding expander, I observed .019” of bullet setback during one trip from the mag into the chamber. Not liking that, I prepared the brass so that bullet setback was reduced to .002”. However, this did not improve accuracy at all. In fact, groups got bigger even after I reworked the loads.
So I started to increase bullet grip incrementally and guess what? I found there is an ideal amount of bullet grip for 9mm pistol accuracy. Too little, accuracy sucks. Too much, accuracy sucks. Just right, accuracy is great. I guess I’ll just have to live with some bullet setback in order to enjoy the best accuracy the gun is capable of.
