9mm Variables

[918v]

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.

 

[R_A_W]

thought you were about to admit to handloading for a Cx4

jk, @308pirate is your guy for this. FWIW my M96 is more accurate @ higher pressures, but could really be something similar to what you're suggesting - e.g. the way I handle/mishandle recoil

 

[918v]

The problem with semi automatic pistols is multifaceted. Generally the triggers suck. They are loosely fitted. And the sight radius is short. In my case, the pistol is tightly fitted, perfectly in fact. But the trigger pull is not great and the sight radius is short. In addition I am putting pressure on the magazine when I rest it on the bench. Then, because the gun is resting, my grip is inconsistent.

Maybe I should just get a red dot and do mag dumps from 7 yards like everyone else.

 

[abn31c]

The problem with semi automatic pistols is multifaceted. Generally the triggers suck. They are loosely fitted. And the sight radius is short. In my case, the pistol is tightly fitted, perfectly in fact. But the trigger pull is not great and the sight radius is short. In addition I am putting pressure on the magazine when I rest it on the bench. Then, because the gun is resting, my grip is inconsistent.

Maybe I should just get a red dot and do mag dumps from 7 yards like everyone else.

My 2011 and CZ's do not approve....

 

[918v]

My 2011 and CZ's do not approve....

Explain

 

[abn31c]

Explain

The triggers do not suck, they are not loosely fitted and sight radius is a red dot.
Please don't roll all semi autos in the same class as a Ruger LCP.

 

[918v]

The triggers do not suck, they are not loosely fitted and sight radius is a red dot.
Please don't roll all semi autos in the same class as a Ruger LCP.

I said generally speaking.

 

[rdinak]

Have you slugged your barrel? Tried any bullets that are .356?

 

[918v]

I tried Zero 125’s which are .356” and they shot like .355” but fit tighter in the case. I’ll do a do-over now that I have a red dot mounted. That will take the aiming error out of it.