Should I trim 45 ACP cases?

[John Hill]

I have always loaded for revolvers and always check case length but am about to purchase a Springfield 1911 .45 ACP and will be buying all of the dies, boolit mold, boolit lube and sizer, etc. Is it usually necessary to trim case length on .45 ACP?

[Virginia John]

I have never found it necessary and I have loaded a ton of them.

[nagantguy]

In 12 years of idpa shooting literally 100 of thousands of 45 acp through various 1911s and Cz's I've never trimmed a single case. Rifle and revolver sure if a case needs it,223 seems to be the one that grows the most for me. Your .45 acp cases will problem wear out before you'd ever need to trim them.

[jcren]

What they said. I load for 3 45's and with a taper crimp I have never found a need for case trimming.

[Char-Gar]

I have always loaded for revolvers and always check case length but am about to purchase a Springfield 1911 .45 ACP and will be buying all of the dies, boolit mold, boolit lube and sizer, etc. Is it usually necessary to trim case length on .45 ACP?

If you are looking for gilt edged accuracy, then consistency in all thing, including case length become important. However, it should be noted that most hangunners don't need and cant use such gilt edged accuracy.

50 years ago, when I was shooting Bullseye competition, most folks trimmed the 45 ACP case to a uniform length. When trying to punch out the X-ring at 25 and 50 yards holding the pistol in one hand, slow and rapid fire, we needed any extra bit of accuracy we could find.

The answer to your question is no. Trimming your 45 ACP cases is not necessary, UNLESS you are doing some fine and far shooting against some high end marksmen and you want to bring home the gold.

[sparky45]

I always thought 45acp cases actually got shorter with multiple shootings? Myth?

[John Boy]

Is it usually necessary to trim case length on .45 ACP? No - but it is absolutely necessary to insure the COAL is correct for proper chambering

[hermans]

I always thought 45acp cases actually got shorter with multiple shootings? Myth?
Not a myth, they do get shorter as you load them. I have been shooting many different types of 45 ACP cases over the years, and I have NEVER come across a case that got longer.

[jmorris]

I am not sure how many hundreds of thousands I have loaded but I have never trimmed a single 45 ACP case. I have trimmed .308, 243, etc down to use them in 45's though.

[Half Dog]

ok...it seems that I'm the odd one. I trim my cases.

[DerekP Houston]

ok...it seems that I'm the odd one. I trim my cases.

I measured the first dozen or so I loaded until I realized I was wasting my time. I'll trim and prep rifle cases though.

[dudel]

I do it once on new brass. Have never had to do it again.

Consistent length gives consistent headspace. Consistent headspace gives consistent ignition. Generally, the more consistent your ammo the more accurate you can be.

Now, if you're planning on plinking cans at 20 feet, you're not likely to see much difference.

[John Hill]

Thanks for all of the info. It will save me a few bucks and a lot of time.
John

[Bayou52]

I've never trimmed a 45 acp case...........

Bayou52

[Wayne Smith]

I measured mine when I started shooting 45ACP and fould that all of them were underlength. Never trimmed any.

[Dave C.]

No! Never trim 45 ACP cases. They start out too short and get shorter every time.

[Sam Casey]

Same no trim for 9mm? Why do revolver shells like 38 Spl & 41mag need special attention? Hot loads?

[Outer Rondacker]

Only if they need it.

[jcren]

Same no trim for 9mm? Why do revolver shells like 38 Spl & 41mag need special attention? Hot loads?
Roll crimps are dependent on the case length. If you don't trim roll crimp cases, some will be over crimped and some may not crimp at all

[Le Loup Solitaire]

Dean Grennell did an article on 45ACP improper case length and its irregular effect on grouping. He screened a large number of cases and found them to be of vastly varying lengths....just about all too short and their being the cause of poor shooting. He devised a jig designed to hold 308 cases so that they could be shortened to a proper uniform length. The resulting cases that he used produced much better grouping than any of the other random cases. It is a known fact...not myth, that 45 ACP cases do grow shorter with firings. There is no need to trim them unless you find one that is too long. You can find his writing on the subject in his book on basics of handloading. LLS

[lightload]

Theoretically, it would seem that pistol cases head spacing on the case mouth would cause ignition problems if they were too short. The reason that they don't is that the extractor limits the case's forward movement--so for all practical purposes, a .45 acp case is head spacing on the extractor. The older heads among us may remember when some .45 target shooters would set head space by seating the bullet out far enough to touch the rifling. This method may be the most precise way to match a reload to a .45 acp barrel.

[Freischütz]

I shoot a 45 ACP revolver and do trim the cases. Trimmed cases make for much more uniform roll crimps

[bangerjim]

Please....do NOT waste your time trimming 9mm and 45ACP pistol brass.

Spend your time trimming bottleneck rifle brass.

I rarely trim 38/357/44/45LC brass....only when absolutely out of spec.

banger

[Mk42gunner]

I think Char-Gar had the best answer.

If you are looking to chew out the x-ring of a Standard American Target from 25 and 50 yards one handed, and can tell the difference, by all means trim the brass. If you are doing anything else, don't bother.

Robert

[wistlepig1]

Same here, never, ever, trimmed 45 ACP.

[454PB]

Strange timing......I've never trimmed .45 ACP brass.

Just today I was resizing a batch of .45 ACP brass that is near it's life's end, probably 12 cycles of loading. I measured a dozen or so, the longest were .889", trim length is .888", maximum length is .898". Unless I'm willing to go below trim length, not much can be done.

[quail4jake]

What Dave C. said! They start out short and get shorter. If you want to go Cadillac, buy new Starline brass and check for uniformity only trimming those over max. length. You will probably never trim them again, just don't let the brass hogs grab your precious little goodies at the range. Remember, straight case autos headspace off the case mouth so gentle goes the crimp and keep 'em long if you can. Rimmed straight cases grow a little as they are fired and length matters because crimp is really important in these. Overbored rifle cases grow and necks get thick and pressures rise...and when they grow a lot the head is about to separate...different game! No, I would not trim .45 ACPs. Thanks.

[CraigOK]

I was never interested in spending the time, return on investment isn't impressive imo

[Char-Gar]

Note: When and if brass is trimmed for the 45 ACP round, it is not because of the length. The purpose is to have a UNIFORM length, which will in turn produce a uniform crimp, which helps with uniform combustion and will end up causing the bullets to play follow the leader a smidge better.

It should also be noted that I am a certified card carrying geezer who started loading my own ammo back in the late 50's. In those days factory ammo was lousy stuff compared to what we have today. Dillon reloaders were decades away, and the notions of "blasting ammo" was an alien concept. We did lots of things in those days, that would seem silly and time wasting by folks today, but we were after the finest ammo that could be produced and we didn't consider our time to be so valuable we could not spend it on precision ammunition. I am still stuck in that retro-groove today.

[brassrat]

I measure and sort by length and stamp, until a full box can be loaded. Because the brass is usually shorter than I want, anyways, I only trim to finish a boxes worth. Any under .888 get scrapped, either then, or loaded to be left, later on, after loosing matches :-)

[r1kk1]

Note: When and if brass is trimmed for the 45 ACP round, it is not because of the length. The purpose is to have a UNIFORM length, which will in turn produce a uniform crimp, which helps with uniform combustion and will end up causing the bullets to play follow the leader a smidge better.

It should also be noted that I am a certified card carrying geezer who started loading my own ammo back in the late 50's. In those days factory ammo was lousy stuff compared to what we have today. Dillon reloaders were decades away, and the notions of "blasting ammo" was an alien concept. We did lots of things in those days, that would seem silly and time wasting by folks today, but we were after the finest ammo that could be produced and we didn't consider our time to be so valuable we could not spend it on precision ammunition. I am still stuck in that retro-groove today.

Nothing wrong with that.

r1kk1

[W.R.Buchanan]

NO.

Randy

[Kevin Rohrer]

It is my understanding that provided straight-wall casings begin at the proper length, then never get longer. I know I have never had to trim mine.

[kungfustyle]

OK, it looks like I'm going to be the odd one out. My wife's star pd is about as finicky as they come. The gun shoots factory very well but cast has been an issue. Even with a egw-guns case checker the gun will still have issues. The solution is to separate out the brass, use a round nose boolit and separate seating and crimping. That way I have a uniform belling of the case and crimp. I just started trimming the brass under .890 and now they all work great no more separating them out just load them up and away we go.