How often do you guys trim your casings? Every time you reload, every five times, never? Just curious.

Sir, FWIW, I don't generally trim straight-wall pistol cases--they don't seem to need it. With bottleneck rifle cases, I trim after each firing. They don't need it every time, but I do it anyway just for consistency's sake.

Hope this helps, and Semper Fi.

Ron H.

__________________
Wishin' don't make it so.

+1. Straight-walled pistol cases don't lengthen with firing.
You will find cheap pistol brass like AMERC that has irregular lengths, but I just throw them out.

__________________
Science plus Art

I agree, I don't trim straight wall pistol cases ever and I do trim rifle cases after each firing. (not that they always need it)

__________________
Freedom is never free!!
SWCA #3437

Never trimmed a pistol case.

I check my 223 Rem in a gauge but only neck size those(bolt action) so they do not stretch much. Trimmed then a few times.

__________________
Still Running Against the Wind

Back in the 80's I trimmed my 44 mag and 357 mag cases all the time!Turns out we were shooting loads that were very high pressure and we were getting brass stretching.At the time we were trying to "kill" 200 meter rams and other tough steel animals and we thought we needed the loads.Now that I have gotten a little older (and I hope wiser) I never have to trim brass and if I do I know instantly something is wrong with my load and or gun!

I trim straight handgun cases when I get them. I run bottleneck rifle case through the trimmer everytime I reload them. You can't have too much consistancy.

I only load .38spl, .357mag and .45acp, so I'm not familiar with rifle and bottleneck cases.
That said, I trim all "new-to-me" cases once, whether they are factory loads fired by me or range brass or purchased empty new brass.
I check a few in my active reloading stash every now and then, but have yet to find one that has grown past the original trim length.

I use Lee Factory Crimp Dies on everything these days, so the typical variations in case lengths between different head-stamps are more or less meaningless, but being a creature of habit, I still trim the first time, and once it is done, it is done forever. (Unless you load at max and beyond)

John

__________________
Age + Treachery = JohnnieB

I also never trim straight wall handgun cases….waste of time. I trim rifle cases when new then check after every firing and trim when needed.

Dennis.

I only reload for handguns. I trim new or brass revolver cases new to me before the first loading. I don't trim auto cases.

I only trim when I load a straightwall case for the first time and then check them for length after that. My experience is that trimming after the first time makes a difference only on roll crimping. The more uniform the case length, the more uniform the roll crimp. It is a small difference most of the time but can be important on high end, slow burning powder loads. Standard deviation can vary because of the greater or lesser pull of the bullet because of the heavier or lighter crimp applied during seating because of variations in case length. While this is seldom an important factor in most pistol loads, it can become at a factor at the long ranges of silhouette shooting. My experience anyway. James

I'm just starting to reload and this has been a very informative thread. Thanks to the originator and all those who have responded.

Add one more to the "First time, new to me trim."

I shoot for consistency, therefore I start with consistent cases.

If I were shooting for plinking, it wouldn't make a bean, but when you are trying to keep it in the center....every time, it makes a difference.

My 2¢!

James57, My thoughts also, When I'm testing loads I want all my cases the same length so the crimps are even and bullet pull is the same.

I trim my bottle neck rifle case as need most are low pressure cast bullet loads and generally don't need to be trimmed each time.

On straight wall pistol cases 38/357 I trim them when new to get the case mouths flush and a good consistent crimp rd. to rd. and trim again when I start notice crimping inconsistency.

On taper crimped case like my 9mm I'm currently working on some load test with brass segregated by or trimmed to various lengths to see if it affect accuracy as well getting a more consistent crimp also how much the brass shrinks after firing and what length it returns to when resized.

I've found case that measure all the way from the Min. length to the Max length I actually found cases that are well below and well about both measurements.

It's a work in progress but I'm a handloader and I like to tinker.

Howdy

The idea behind trimming is that once cases stretch beyond their maximum recommend length the shooter should trim them back to the 'trim to' length. Most manuals set the 'trim to' length at either .005 or .010 less than the maximum length. They should not need trimming again unless they exceed the maximum length.

The reason cases stretch is from the pressure generated inside the case when they are fired.

Personally, I have never trimmed a single pistol case. They never develop enough pressure to stretch at all. I load 45 Colt, 45 Schofield, 45 Auto Rim, 45 ACP, 44 Special, 44-40, and 38 Special. None of them have ever stretched beyond the maximum length, so I never trim them.

I trim all my 9mm Makarov cases (9x18) only because I make them from 9mm Luger cases (9x19). Tedious, but Luger cases are available for the picking!

The only reason I can see for trimming straight-walled cases is if you're into precision target shooting where ultra-consistancy is all important (Trimming each case to an exact length, measuring every powder load, weighing each bullet, etc.). For the average guy punching holes for practice or clanking steel, it won't make much difference. I measure a case once in a while and have never found once to long.

I'm also of the trim them the first time new to me crowd for the straight walled cases. It really only helps/effects the roll crimped reloads. Some of the new or once fired brass is over the recommended oal & causes problems with some of the cast bullets I use due to the small crimp groove of the bullet design. After they've been trimmed I've never had a problem.

The necked down hp cases get trimmed every reload.