I have a lot of mixed 45 acp brass. a lot of it is under 0.893 .any where between 0.884 to 0.889.if I sort to length and taper crimp.to.47 should I stay with the same COL.

That is only .016", not much more than the thickness of the case mouth. Any cases that are within .015" the difference in length can be ignored as it doesn't make any difference! Don't waste your time and energy sorting by length!

I have never had any problem using any .45 ACP brass from any source. Never trimmed a single .45 case in over 50 years of loading it. You do not have a problem.

Are the cases sized? They'll grow a bit once you size them.

I have used the same 45 ACP cases 20+ times without measuring them.

I once sized several hundred 45 ACP cases for use in USPSA matches. I don't know that it made any significant difference in accuracy or consistent velocity. I do know that they were quickly lost during matches as you don't get to pick up your brass after you shoot each stage.

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VCDL, GOA, NRA

It sounds like another useless thing to worry about.

Like DWalt have been reloading .45ACP for over 50 years. I have never sized a piece of .45ACP brass.

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USMC 69-93 Combat Pistol Inst.

I keep about 8-10,000 each of 9mm and 45ACP on hand, primed and ready to load. I made the effort to sort out 500 or so of each for load testng.

When I'm deciding between 2 finalist loads at 50 yds with a Ransom rest, the brass will be once-fired, one brand, +/- .001" long and +/- 0.2 grains in weight after priming. The bullets and powder charges get similar scrutiny. Handloading is a separate hobby unto itself.

When that fun exercise is over, and I've settled on the most accurate load at 50 yds (usually 3-4 MOA) I load up a few hundred in miscellaneous, unsorted brass. I've Ransom tested bulk loads enough time to know my sub- 2" 50yd groups are likely to double in size. I don't shoot formal bullseye; I just blaze away at paper and steel. I'll mark brass to be culled for various reasons (usually when crimping) but never weigh or measure it for general use.

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Carry.."hope" isn't a strategy

When I started reloading 45 acp in 1967 I had been picking up once fired range brass for a couple years ... I knew I was going to get a 1911 .
I opened the Lyman Cast Bullet Handbook ... and there found
"Trim to length" .... .895" So , with my Bair Case Trimmer I trimmed them all to that length . The sized cases wouldn't fit on the trimmer spud ... so every one got trimmed in the fired state . The cases that were short just didn't get any trimming and went in the box .
I haven't trimmed any of them again ... I shoot & reload the brass untill cracked or lost and replace from the bucket .
With taper crimping and the low pressure of the 45 acp brass doesn't seem to need much trimming after you get all your brass to a fairly consistent length ... I love reloading the 45 acp ...it's a Sweet-Heart !
Gary

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Certified Cajun
NRA Member

I measure 38 and 45 brass, but not for some compulsive search for accuracy. The only reason I measure and trim 45 and 38 brass (the first and only time) is to get a consistent length and therefore a consistent crimp. I tend to do them in batches of ~1,000 and I don't want to be fiddling with a crimp die setting in the middle of a run.

45 ACP will never need trimming.

Now 44 Special and 45 Colt will need trimming if you “hotrod” them.

Post #8 covers it. If you want accuracy?

Was issued 50,000 rounds of WCC Match 85 headstamped ammo to train my Marines with. All the IMI was being destroyed as unreliable. We were a Marine Barracks and training allocation of ammo was priority one. They gave use WCC Match to train with. Just wasted on shooting steel targets and familiarizing with. The 1stSgt. and I just about cried. The good thing was I ended up with three ammo cans full of once fired Match brass. No need to worry about cases, just the bullet and powder weights....then go for the gusto. Still have a completely full ammo can of the once fired Match brass tucked away.

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USMC 69-93 Combat Pistol Inst.

There's more problems with neck tension than case length with range brass. I've never checked the case length of any range brass. I have culled brass during sizing due to the tension I'm not feeling with the press.

Pistol brass that head spaces on the rim just isn't a yuge issue. Note that COL for commercial ammo is all over the place.

Trim your rifle brass to spec.

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That's just somebody talkin.

Bullet hold, neck tension of 45acp range brass runs from 45 pounds to past 100 pounds to move a 200 gr lswc. My testing.

Range brass produces poor accuracy, even at 25 yards.

The longer the trim length, the better the accuracy. (Never need trimming)

Don’t worry about it.