Trimming Pistol Brass

[shoe]

I've always been told that trimming pistol brass is not needed for safety since in the life span off the case (9mm for me) it will crack before it will go over max OAL.

But what about for accuracy? I do use a RCBS bullet seater w/ no crimp and then a lee factory crimp. This weekend taking my 226 out to the range I noticed some rounds going awry @ 25m-50m. I'd like to think this was some brass that was way longer than anything else in my brass pile, and if I really wanted consistent ammo should I trim the brass?

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[Nwcid]

If you want to trim pistol brass then you sure can. In theory the more things that are all equal the better you loads should be. Now with that said on most pistols the time you spent doing the extra steps would do very little to improve things. You said you "would like to think" that is the problem but you dont know. So if you think that is the problem why not test it before spending lots of time on something that may not matter. The one time I can see trimming pistol brass would be if you had a "high" power hunting style gun like .500, .460, even .44, ect.

Even on rifles to a certain extent it can make little difference. Many years ago I loaded up some round for my first .308, a Rem 700P LTR (so accurate rifle). I had all same head stamped brass, I cleaned all the primer pocket holes, I trimmed them all, I used BR primers, I weighed out each charge by hand, I did every step in the book on my single stage press. This gun shoots just under an MOA. A couple years later I got a Bushmaster Varminter (24" target AR). I never expected it to be as accurate as a bolt gun because that is what everyone says. I loaded a bunch of ammo on progressive press using mixed head stamp brass (not mixing mil and civ brass though), no cleaning outside of tumbling, standard CCI primers, pulled surplus powder that comes in 8lb jugs. This gun also shoots under MOA.........

Now I am not competing with either of these guns so that extra mm of accuracy is not critical to me. I am not saying to do it one way or another but telling you to TEST your loads and steps to see what works for you in each gun. While I did not notice a difference between those 2 guns/loads I have another new target rifle that I am working on now. On that gun I will be hitting every step to load the 100% best rounds I can for it.

 

[shoe]

This was my first time noticing rounds behaving like this, I group solid and if I do miss do to my error it is only by a small amount which I can see on paper or it just passes paper/steel. The rounds that went awry were WAY off, approx 5-8ft above or to the side of the target. If I was further back I could blame it on myself but at 25m-50m I don't think it was my error for rounds to hit off target by that much.

What would be the best way to test this and take as much human error out of the equation to achieve good data? Rest the pistol on the bench and shoot? or are there pistol bench mounts of any sort?

 

[Nwcid]

To test is load up some of the long cases and short cases knowing where they are in your mag. Shoot at your target. If you can see a difference (knowing what round is what) then you can say it is the brass length.

 

[deadshot2]

The world of pistol brass and rifle brass are vastly different.

Pistol brass falls into two categories. One where the case headspaces on the rim and the other where it headspaces on the case mouth.

Pistol Cases with rims often use and in some cases require a roll crimp. In this instance the uniformity of the crimp, which can affect accuracy, is dependent on uniform case length.

For pistol cases used in an autoloader, these more often than not index on the case mouth and use a taper crimp. Trimming is pretty much optional as the taper crimp is not as much to hold the bullet in place as it is to make sure that any belling of the case has been smoothed out, in order to ensure reliable feeding. My experience with 9mm cases is that trimming is a waste of time. Most cases I have encountered are too short and no metal is removed, even after several firings.

Case growth in rifle cases is not so much from the firing, but from the sizing and expanding process.

In short, I don't trim any 9mm cases and only those rimmed pistol cases where a roll crimp is required (magnum loads with 296 is a good example).

 

[shoe]

what does a rimmed pistol case look like?

 

[deadshot2]

what does a rimmed pistol case look like?

This is a start

.38, .357, 44's, .45LC and on, and so forth.

Unlike cases like these

 

[shoe]

Wow again I feel like an idiot haha, just didnt put 2 and 2 together... for some reason I was thinking of a rim on the case mouth... ughhhhhh. I need coffee

 

[Gunner3456]

If you have a bunch of new (to you) used brass, especially if it is mixed head stamp, I would sure run it through the trimmer the first time just to be "sure."

Beyond that, Deadshot2 nailed it. Pay attention, soldier, LOL.

 

[Throckmorton]

be sure to size before trimming.
I can't believe that case length would make a difference measured in feet
.Don't hate me but this is either operator error,or maybe the bad ones got skpped on the crimping operation? Feet is hard to fathom,I used mixed revolver brass all the time,with 'cheap' Italian guns,and they are only off by 7" at the very most at 25 yards,seldom that much.

Let us know how it comes out.

 

[Gunner3456]

be sure to size before trimming.

Good point.

I can't believe that case length would make a difference measured in feet
.Don't hate me but this is either operator error,or maybe the bad ones got skpped on the crimping operation? Feet is hard to fathom,I used mixed revolver brass all the time,with 'cheap' Italian guns,and they are only off by 7" at the very most at 25 yards,seldom that much.

Let us know how it comes out.

I'm really curious too. It's a new one on me. I believe him, but I just can't even come up with one idea what could cause it to that extreme.

 

[shoe]

be sure to size before trimming.
I can't believe that case length would make a difference measured in feet
.Don't hate me but this is either operator error,or maybe the bad ones got skpped on the crimping operation? Feet is hard to fathom,I used mixed revolver brass all the time,with 'cheap' Italian guns,and they are only off by 7" at the very most at 25 yards,seldom that much.

Let us know how it comes out.

Honestly I don't believe it either. I dont mind you saying operator error, I thought it was me for a while as well but by that much is A LOT for me unless I sneeze lol. I could see possibly not crimping hard enough on certain rounds since my bench isnt the most stable thing in the world but am working on it.

But I did leave out one piece of info: my bullets.

I've been using electroplated bullets from xtremebullets recently, (just switched over from montana gold cause they take way too long to ship out here even though they're in Montana) and started using a lee factory crimp die on them. Could it be possible that I crimped too hard and ripped through the plated? So when the round comes out its missing a piece? Contacted xtremebullets today and they did warn me about overcrimping but said it was good that I was using the Lee Factory Crimp because they usually dont cut through the plating unless you crank the collet all the way down.