Pistol case trimming

D

DarthNul

New member
I've been loading 9mm, .40S&W and .45 Auto for several years now and I never much worried about trimming cases between loadings.

Now I'm starting to load for some hotter calibers, namely 10mm auto and .44 Remington Magnum. Do I need to start worrying about trimming those or are the cases likely to crack before that's an issue?
 
I've got .45 Colt brass that I have reloaded almost 30 times that I have never trimmed. The loads on this brass has ranged from mild to moderate loads. I don't believe you will have to worry about trimming, but it never hurts to measure occasionally.
 
Now I'm starting to load for some hotter calibers, namely 10mm auto and .44 Remington Magnum. Do I need to start worrying about trimming those or are the cases likely to crack before that's an issue?
Click to expand...

There is an active thread that starts with crimping crimped cases with a Lee factory crimp die. I have Lee factory crimp dies, I do not use them but I have them just in case. This thread is about trimming pistol cases; when I crimp I want my crimps to be all the same if the crimp controls accuracy. Before the Internet Lyman suggested crimping could be a bad habit; seems crimping can lesson bullet hold.

So I suggest if reloaders do not trim cases to the same length when crimping they should sort cases by length (height if the case is standing). It is possible to speed sort cases by length.

F. Guffey
 
Thanks for the replies!

I have one vote for trimming if the cases will be crimped. That makes sense for achieving consistent crimps.

Right now I'm only crimping my .44 magnum due to the very real threat of bullet setback from heavy recoil. I don't crimp for the other calibers because they all headspace on the case mouth. I just get rid of the "bell".
 
>Right now I'm only crimping my .44 magnum due to the very real threat of bullet setback from heavy recoil

Unless your .44 Mag is a semi-auto, bullet set-back is NOT an issue. You crimp because the recoil can force the bullet OUT OF THE CASE and jam the cylinder.

1) cases that head space on the case mouth--never trim. Best accuracy comes with minimum head space. This means size and measure and set aside the longest and compare accuracy.
2) taper crimp--length is not important
3) roll crimp--many believe length is important. it may be for highly accurate, long-distance rifle shooting. For pistols, you roll crimp into a crimp groove and cannelure. In both case, the width of the "groove exceeds the case length variation you have. Size a case and seat the bullet so the case mouth is just below the top of the groove/cannelure. This is all you need to do, unless your handgun is shooting 0.25 MOA groups
4) OCD and you must "play" with your cases--trim them all to "trim to length" and be happy. You may have thrown away 1-5 MOA in terms of accuracy, but you'll "feel" better, and that can give you confidence.
 
Plinkers I never trim , but hunting rounds get a trim not so much for o.a.l but to make sure the mouth is straight / level for a equal even crimp around the bullet .
 
Unless your .44 Mag is a semi-auto, bullet set-back is NOT an issue. You crimp because the recoil can force the bullet OUT OF THE CASE and jam the cylinder.
Click to expand...

Thanks! The .44 is my first and only (so far...) revolver. I guess I'm still thinking in semi-auto mode.
 
No. I've reloaded .44 Magnums for 27 years and have never trimmed a case. I have reloaded everything from 123 gr. balls over a dusting of Bullseye to 265 gr. RNFP T-Rex killers over heavy loads of WC820. There has never been a variation in case length large enough to affect crimping consistency (I roll crimp into the crimp groove/cannalure and disregard book OAL). I have produced some very accurate loads 1 1/2" groups @ 30 yards from my Dan Wesson 44H and my Ruger SBH. My other handgun brass (.38 Special, .357 Magnum, .44 Special, 45 ACP, and 9mm) is treated the same...
 
Handgun cases rarely need trimming. Can't recall ever do it in 40 some years. Mind you, that applies to straight walled cases. Stuff like a .357 Sig, being bottle necked, might need it. A .357 Sig is out of my price/need range though.
A 10mm Auto isn't that hot. And you really don't have to sort them by head stamp.
"...the very real threat of bullet setback from heavy recoil..." Only applies to heavy loads.
 
Never trimmed

I reload 5 different handgun calibres. I've never trimmed any of them in 30 years!! 9 mm, .357 , .38 Spl, .45 , .44 Mag
I do tumble them clean. This will make cracks and splits show up.

But when I became more of a rifle guy, I soon found out that my .308 would not chamber due to stretching. So trimming became necessary.
 
Call me OCD or anything else if you want, but I trim .357 mag, .44 mag, .460 and .500 S&W brass. I find there is enough variation in the length sometimes to affect the crimp more than I'd like. Oh yeah, .454 brass too.

If I don't trim the brass, sometimes the crimp is too great and sometimes there is no crimp at all.

YMMV
 
For all but one of my bottom feeding auto's not gonna happen. The one I DO trim or square up the mouth is on my 10mm. I hunt with it on occasion, and have seen differences in the group sizes between trimmed and not trimmed.

I have been loading and shooting revolvers for most of my 50+years. I started out with plain jane 38 SPL before I was a teen, and as I grew older I got more and more interested in just how well I could make them shoot.

I look at it like this, I do all sorts of things to make a hunting rifle shoot sub MOA why should I not treat my other hunting ammo the same? Realistically I want them all to shoot as good as they can. Trimming isn't a huge deal as I usually do them in batches of around 100. I pull out a handful and measure. Then I pick the shortest one of the batch and set the trimmer to that one. I might get quite a bit off a few, simply square the mouth of more, and only polish a few more, but they all end up withing a couple of thousandths, and when I crimp they are all getting the same pressure on the bullets. When my Redhawk was scoped with a 4x Leupold and some carefully loaded hot 180gr Sierra's, I have shot plenty of 1" or slightly above groups at 100yds.

If you want to know what got me started in this process, it was reading Elmer Keith and how he worked up loads for accuracy. Granted he shot 100 times more than I probably ever will, but the techniques are still the same. Here is a link which contains some great reading. Scroll down a bit to the two write ups for handgun loading. Elmer Keith Memorial Website

If you don't think that just the crimp can effect the accuracy of a load, here is a picture of the identical load with only the crimp changed,
attachment.php


The group on the left was too much. The ones on the right were backed off only about 1/8 of a turn if that much. They were shot at 40yds, standing and using a two hand hold. The revolver was my friends S&W 657 Classic Hunter in 41 magnum of my friends. The high and low ones were totally my fault due to the smooth trigger it has. That was also the first time I had shot it. The point is that a little bit of difference, can make a big difference.
 
After several times reloading my 44 mag brass I checked the case length. Many of them had stretched so they were trimmed. My 357 brass all measured within specs. None of my pistol brass has ever been trimmed.
 
After several loadings the cases will take on that knife edge look around the mouth of the cases so you just might want to trim slightly for the purpose of restoring the squared away case mouths and improving appearance.
 
I used to trim my rimmed pistol brass for a nice even crimp. No more. I don't bother for .38 Sp, on my .357 and .41 I use Lee collet crimpers, they aren't so sensitive to case length and are much easier on brass.
 
For auto pistols I haven't found a need to trim yet. For 357 mag I used to get a lot of stretching, which I attributed to the Lee FCD. Once I stopped using that die, my cases stopped stretching. Now I just use a simple roll crimp as provided in the Lee seating die.
 
Slight variations in length can affect a role crimp, but if you load revolver rounds a box at a time, and keep the same matching brass together you will eliminate case length variations significant enough to matter.
 
You must log in or register to reply here.
Back
Top