Trimming 45 ACP brass

"Could this be an issue in a .45 ACP revolver when you aren't using moon clips? Wouldn't they have to be near perfect for length since they seat on a rim in the cylinder and the firing pin can only move so far?"

Generally not. In a S&W 1917, for example, the case mouth seats on a chamber front ledge. There is no case rim; you don't need one. And you don't need half moon clips. I never use them in mine. And I never trim the cases. There is plenty of tolerance in the design, and the firing pin extends far enough to dent primers deeply and reliably.

I use all these untrimmed .45 reloads in the S&W 1917, five or six 1911 variants, a 1928 Thompson, and a bunch of others. All rounds work in everything, if recoil impulse is correct for the autos/semiautos.

In the Colt 1917, you can't do this. The chambers are bored all the way through, and you must use moon clips, or rounds will drop all the way into the chamber, beyond the reach of the firing pin.
 
Case length variance can cause crimp differences when your roll crimp, and that can affect accuracy. When you use a taper crimp variance will not be noticeable in the accuracy unless there is considerable difference.
 
The best I could offer would be to spend the time chamfering the mouth inside and out. It improves the reloading aspects. Otherwise, shoot 'em up! It's a great round.
 
To each there own, but I trim, chamfer and deburr all my new and new-to-me brass before reloading it the first time.
For .45acp, I use a Lee length gauge that has been ground down to produce a 0.895" case length.
After that one time, it is straight from the tumbler to the press.

That may be overkill to some, but not for me since I wash my fired brass before I tumble it. :D
 
My 2 cents worth they all seem to short to trim. But in my foolish youth I made a batch all the same length, but when they were shoot couldn't tell a nickles worth of difference so never did that again.
 
HEAD0001,
A light taper crimp when done properly doesn't actually crimp so much as it removes the flare from the expander die step and just snugs the brass up to the bullet. So the case length is pretty much irrelevant. No need to trim, but if you are so inclined then there's no harm in it either. I have chamfered and de-burred all the brass I have dedicated to my 625, but don't bother with that for my autos as most of that is range brass anyway. Doesn't seem to matter at all in over 20 years doing it that way.

If I were loading heavy rounds for the 625, probably in AR, with bullets that have a definite cannelure, then I would go the whole route of trimming, etc., because I'd be using a roll crimp.
 
Trim .45 ACP brass. Nope. Never needed it. Use a taper crimp. That eliminated brass length as a concern. Works with lead or jacketed bullets. This has worked for me for many thousands of rounds of handloaded ammunition. HTH. Sincerely. bruce.
 
JohnnieB said:
To each there own, but I trim, chamfer and deburr all my new and new-to-me brass before reloading it the first time.
For .45acp, I use a Lee length gauge that has been ground down to produce a 0.895" case length.
After that one time, it is straight from the tumbler to the press.

That may be overkill to some, but not for me since I wash my fired brass before I tumble it. :D
Click to expand...

Yes, new as in in brand new brass should be sized and trimmed, chamfer etc. Never know what length they might be. Only handgun brass I purchased new was 45 Colt and the Lee trimmer did cut a few of them so I know they are all the same.

I have washed a lot of brass before tumbling. I have a 5 gal bucket to put my vinegar, salt and water in and a 2 ft square frame of 2 x4's with hardware cloth to drain them on the driveway. They can be loaded when dry, but a quick tumble shines them up. Media last longer that way also.
 
There is a minum and a maximum length. Certain bullets, especially cast have differing trim lengths for brass so when you crimp in the canlure your C.O.A.L is correct. When you tapered, the more goes in the die the more taper there will be, so .888 will have less taper than .895 length. Most importantly this cartridge head spaces on the case mouth so don't roll crimp if semi auto. This head spacing off the mouth on untrimmed differening lengths will hold the bullet at different distances from the throat of the barrel I think, might check that on me and make sure. I have been wrong before. But for sure if head spacing is inconsistant, you groups will be. This distance the bullet travels to barrel is called bullet jump which is a whole nother subject. Varing bullet jump will greatly effect accuracy and REALLY important Pressure (most critical when bullet leaves brass and hits throat of barrel). So the pressure in you load book will be off. If the lengths are different you will have varing pressures, bullet grip (friction how tight brass holds bullet), and bullet jump. These phrases can be researched for yourself. I've proved to my self how far is too far in the process by shooting on a slead to test loads. I have friends who don't even clean their brass, I actually enjoy reloading and do it all from casting to neck turning. As long as your safe it depends on what your after. I shoot with friends who are doing just as the others on your post, and their happy. I thought it would be good to get the otherside of the coin.
 
I may have missed seeing it mentioned, but most .45 ACP is headspaced by the extractor holding the cartridge against the slide. Since they don't actually headspace off the case mouth as designed, trimming to the same length makes no difference.
 
The crimp is NOT what holds the bullet in the case. When the case is resized, the entire length of the case is made smaller, creating a "press fit" when the bullet is inserted. You should only flare the case enough to get the bullet started without shaving lead. Case wall tension is what holds the bullet, the crimp die should only remove the flare.

MichiganScott, you have bad information.
 
MichiganScott said:
I may have missed seeing it mentioned, but most .45 ACP is headspaced by the extractor holding the cartridge against the slide.
Click to expand...

I've seen this comment launch multiple opp-topic pages of debate. :D

On topic: It may not be necessary, and everything in my OCD head tells me it's not necessary, but I still trim my pistol brass.
 
Last edited:
Been re-loading (38 special, .357 magnum, 45 acp, & 45 Colt) for 35 years and I don't even own a trimmer.

I also load .38-55 and .45-70 rifle calibers and have never trimmed them either. I don't load to max and I have never had a jam, FTF, or any problems.

Chief38
 
Well from all the responses, it sounds like you don't have to trim but it won't kill you if you do.

I always trim my handgun brass before I load it for the first time to get them to the same length, it sure helps getting that crimp consistant and not bulging cases. I don't think it hurts the accuracy either. It sure is a pain in the neck though.
 
My feeding is that if you shoot high powered rifle cartridges often enough they will eventually require some trimming.

I honestly do not know any re-loaders that trim handgun cartridges though.
Probably because most re-loader's do not load to HOT spec's. and use them for Target Practice and informal plinking or competition where hot loads would be a disadvantage.

I suppose if you are bored and want to add another step to the process, go ahead and trim although IMHO you could spend the time doing more enjoyable things.

Chief38
 
I have never trimmed .45 Auto brass or any handgun brass for that matter. It's just not necessary and a total waste of time IMO.
 
45 ACP brass will tend to shrink with multiple firings.
In a 1911, this does not seem to matter as most, if not all, 1911's will headspace with the extractor.
I did have a Sig P 220 that would not headspace with the extractor and would fail to fire short brass- a PITA
I taper crimp all my 45 rounds, as a roll crimp, even on 45AR brass, makes some rounds too large to chamber in my tight 625JM.
 
I have never trimmed any handgun brass. At one time I did select single manufacturers headstamp brass for bullseye pistol matches.
 
When you trim your new brass do you measure them all first and trim to the shortest length? Probably not.
You just trim so that none are OVER a certain length.
 
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