Trimming Auto Pistol Cases is Unnecessary & Waste of Time So That’s What I’m Doing

I do sort 9mm by headstamp and I have sorted them by length, but it always took too much of my time so now I set up my Lyman M-die to flare the .740 and up, length cases, and when I get a shorter one, I won't be able to get a bullet to stick in the case while I'm loading.

I pull those cases off my LNL shell plate, which is easy, and set them aside for later to recover my primer, then they go in the recycle bucket. I don't get very many anymore. Maybe two or three per couple hundred, but in the beginning I threw some away for sure.

My seat and crimp dies are both micrometer dies so it's easy to make changes on the fly if I need to.
Yes, I have to de-prime some when I'm done but that doesn't take very long.

But it's much faster for me than sitting there with dial calipers and measuring each and every one. I realize I don't get the longer ones out (above .750) but I've never noticed any problems caused by them and don't want to become to OCD about them.
Once my dies were set up the way I wanted, finding the shorter ones now blends into the entire loading process instead of being a separate time-consuming step.

Just another way of doing the same thing.
 
tightgroup tiger said:
I do sort 9mm by headstamp and I have sorted them by length, but it always took too much of my time so now I set up my Lyman M-die to flare the .740 and up, length cases, and when I get a shorter one, I won't be able to get a bullet to stick in the case while I'm loading.

I pull those cases off my LNL shell plate, which is easy, and set them aside for later to recover my primer, then they go in the recycle bucket. I don't get very many anymore. Maybe two or three per couple hundred, but in the beginning I threw some away for sure.

My seat and crimp dies are both micrometer dies so it's easy to make changes on the fly if I need to.
Yes, I have to de-prime some when I'm done but that doesn't take very long.

But it's much faster for me than sitting there with dial calipers and measuring each and every one. I realize I don't get the longer ones out (above .750) but I've never noticed any problems caused by them and don't want to become to OCD about them.
Once my dies were set up the way I wanted, finding the shorter ones now blends into the entire loading process instead of being a separate time-consuming step.

Just another way of doing the same thing.
Click to expand...
Well I haven’t decided what or whether I’m going to do but for sure if I had to go through what you described I wouldn’t add anything new. In fact I might be buying factory ammo vs reloading;)
 
Atavar said:
I too like to trim my .45acp and 9mm brass for a more uniform flare and crimp.
I do sort my brass and trim to the upper middle of SAAMI range and toss any short brass in the recycle bucket.
It just makes things go smoother. Aside from perhaps wasting a little of my time it hasn’t caused any problems.
Click to expand...
I remember your saga. I don’t have that issue so if I do measure, separate, and trim it’ll be hard for me to explain why;)

While I completely accept @LiveLife ‘s opinion as being valid, it seems to me trimming 9mm or 45acp is like chicken soup, can’t hurt provided it’s not done repeatedly thus shortening (pun intended) case life.
 
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Slamfire said:
Trim to your heart's content. It won't hurt anything, and in time, you will get tired of doing it, because it does not help anything either.

I never shot bottle neck pistol cases like the 38/40 or 44/40. Maybe they need to be trimmed just like bottle neck rifle brass.
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Good point but since it’s pretty much a one and done exercise what’s to get tired of?
 
I want to get a batch of new brass and trim and uniform it as much as possible to see if it makes a difference. However after reloading 9mm for 2 years I still haven’t done so.

I set my calipers for max length and any cases that passes through are good. I either trim or discard longer cases. If the more uniform cases are more accurate, I can’t shoot the difference.
 
CQB45ACP said:
Well I haven’t decided what or whether I’m going to do but for sure if I had to go through what you described I wouldn’t add anything new. In fact I might be buying factory ammo vs reloading;)
Click to expand...
I'm not sure I understand what you mean by "If I had to go through what you described". I bought the mic dies at 1/2 price. Like $50.00 each. My other dies worked fine. but I wanted to be able to have a reference point of how much I was changing the dies so I bought the mic dies.
As far as picking out the shorter cases by setting my M-die a little higher, that's just a lazy man's way of length sorting. If the bullet won't set in the case the case is to short for my crimp die so I pull it off the shell plate. Keeps me in a range of .740-.750 case length so my crimp die is in it's happy place. Easy Peezy.
 
tightgroup tiger said:
I'm not sure I understand what you mean by "If I had to go through what you described". I bought the mic dies at 1/2 price. Like $50.00 each. My other dies worked fine. but I wanted to be able to have a reference point of how much I was changing the dies so I bought the mic dies.
As far as picking out the shorter cases by setting my M-die a little higher, that's just a lazy man's way of length sorting. If the bullet won't set in the case the case is to short for my crimp die so I pull it off the shell plate. Keeps me in a range of .740-.750 case length so my crimp die is in it's happy place. Easy Peezy.
Click to expand...
Well in part it’s my reflexive reaction to anything progressive related. I’m a small volume shooter/reloader with a T-7 (glorified SS). No offense intended.
 
I didn't take any offense to it. I know you don't use progressives and don't load a thousand at a time like I do. That shortcut saves me a lot of time and when my cases are already sorted by headstamp, the case lengths are much closer to each other than mixed headstamps would be, so it's not much of an inconvenience to set my dies this way and my finished ammo is also more consistent this way in case length variances and OAL due to the different lengths effecting my seating length and my crimps being more consistent.
I've notices when I was trying to seat and crimp with the same die, with mixed brass, my OAL variance was much higher than it is now.
I can see how this wouldn't look as appealing with loading on a single stage.
 
Just finished sorting by length all my sized & unprimed Winchester 45acp cases.

Whether I decide to trim or not I’ll hereafter load by length. But how? What length?

I have three basic groups so far:
.893 and over, comprise about 1/4
.890-.892, comprise about 1/2
.889 and under, comprise about 1/4

I think I’ll load only from the long group.

Unfortunately I have about 100 Winchester cases already loaded and about that many already primed & expanded so I don’t know their case length.

This latter point is significant because I am in the midst of a Winchester-only loading phase/rotation and only use/reuse those cases I’m already using.

I’ll have to decide whether to cull & replace any under length cases.
 
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If I had to trim 9mm cases. I would stop reloading 9mm. I hate trimming.

handling or holding that tiny little case by the hundreds up to any trimming tool, device, scissors....Nope.
 
Walkalong said:
Bored? 😁😁
Click to expand...
All these fellers talking about saving time and shortening the reloading process… like they got other things to more important or something. Meanwhile Ol’ Glenn’s looking for ways to spend more time with his brass and press. I gotta say, there’s something to be said for not needing or wanting to be in a hurry.
Life is just too short to be in a hurry.
 
LiveLife said:
Don't ... Do ... It.

Straight walled semi-auto pistol cases like 9mm and 45ACP that need to headspace off case mouth should not be trimmed as repeated resizing and firing will shorten the case length over time due to resizing die carbide ring not reaching all the way down to case base.
After too many reloadings, resized case length can get short enough to start headspacing off extractor as chambered round won't seat case mouth with chamber.


Cancel the order ... You will thank me later.


As close to SAAMI lengths, longer the better.

If you want consistency, sort by resized length but DO NOT TRIM.

SAAMI lists .754" for 9mm case length and for my Lee Pro 6000 and 2023 Pro 1000 finished OAL consistency testing, I measured resized case lengths and chose .750" as typical average length to set my case mouth flare amount and taper crimp die adjustment (As longer case will apply more flare/taper crimp but didn't find too many of those as shorter cases were more common) - https://www.thehighroad.org/index.p...r-oal-consistency.911743/page-3#post-12446468
Click to expand...
Years ago....Trying to avoid shaving with LSWC and a 3 die set up on my Pro 1000, I made the mistake of trimming a big batch of 45ACP. After shooting them they measured about 0.887 which is 0.001 below SAMMI minimum (0.898-0.010). They have been that way a LONG time and do not appear to be getting any shorter. I am not too worried about it but it begs the question:

How do you know if you are headspacing in the extractor when they "plop" fine and do not appear to drop in the chamber past the bevel of breech?

I now only used 4 dies sets so I only did that one set years ago. But I am still using that brass along with newer brass I have never trimmed.
 
refuse2bafool said:
How do you know if you are headspacing in the extractor when they "plop" fine and do not appear to drop in the chamber past the bevel of breech?
Click to expand...
By doing the "Plunk Test" for straight walled semi-auto pistol cases - https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389

The "Plunk Test" is essentially checking these three things:
  1. Dummy round (No powder, no primer) or test/finished round's dimensions fit the chamber
  2. Bullet nose and shoulder do not hit the start of rifling
  3. Resized case length is not too long or short
Here's comparison graphic from @Walkalong thread which illustrates all three items more clearly - https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/

index.php


When we perform the "Plunk Test", we are: 1) Checking to see if the dummy/test round falls into the chamber freely with a "plonk" (Hence the "Plunk" test) to verify round's dimensions do not exceed chamber dimensions, 2) Chambered round freely spin to verify bullet nose/shoulder do not contact the rifling and 3) Checking to see how high/low the case rim is relative to the barrel hood to verify resized case length.

Going right to left in the above graphic with A) through D) representing left to right labeling:

D) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is too long and slide won't go into full battery as case rim protruding above barrel hood will prevent full lock up.

C) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is headspacing off chamber and slide will go into full battery as case rim flush with barrel hood will allow full lock up (As indicated in the graphic, this will allow better sealing of gas as case mouth seals with chamber wall and produce improved accuracy).

B) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is shorter than chamber to breech wall face distance and chambered round case rim can start to contact extractor to headspace off extractor (When powder is ignited, expansion of gas will push case rim against the breech wall face pushing case mouth away from the forward part of chamber, leaking more gas). If you use mixed range brass that's been reloaded multiple times, resized case length can vary quite a bit and neck tension/taper crimp amount could vary and addition of variance of gas leakage around case mouth all can tolerance stack to affect accuracy (Trimming case mouth to same resized length can improve flare/taper crimp amount consistency but won't improve gas leakage).

A) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is so short that chambered round case rim is held back by extractor with case mouth dangling away from forward part of chamber to affect accuracy (It's like shooting 40S&W in 10mm barrel). When powder is ignited, expansion of gas will push case rim against the breech wall face pushing case mouth further away from forward part of chamber leaking more gas.

refuse2bafool said:
Years ago....Trying to avoid shaving with LSWC
Click to expand...
Another thing with using mixed range brass that can vary in resized case length; when I am setting up dies, I will measure resized case length of sample brass to identify "median/average" range of resized case lengths. When determining Max OAL, I will tend to use shorter resized case length as longer resized case length will allow less bullet nose/shoulder to protrude above the case mouth at the same OAL. (Using shorter resized case length to set flare/taper crimp amount will allow more flare/taper crimp with longer resized case lengths to help prevent shaved bullet, especially for seating/taper crimping in the same step, and skosh more taper crimp to not hang up flared case mouth with chamber wall).

If you are after utmost consistency, you can sort for same headstamp and same longer resized case length that will apply more consistent flare/taper crimp amount with more consistent finished OAL and more consistent neck tension/bullet setback - https://www.thehighroad.org/index.p...e-consistent-oal-on-progressive-press.921633/
 
Last edited:
LiveLife said:
By doing the "Plunk Test" for straight walled semi-auto pistol cases - https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389

The "Plunk Test" is essentially checking these three things:
  1. Dummy round (No powder, no primer) or test/finished round's dimensions fit the chamber
  2. Bullet nose and shoulder do not hit the start of rifling
  3. Resized case length is not too long or short
Here's comparison graphic from @Walkalong thread which illustrates all three items more clearly - https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/

index.php


When we perform the "Plunk Test", we are: 1) Checking to see if the dummy/test round falls into the chamber freely with a "plonk" (Hence the "Plunk" test) to verify round's dimensions do not exceed chamber dimensions, 2) Chambered round freely spin to verify bullet nose/shoulder do not contact the rifling and 3) Checking to see how high/low the case rim is relative to the barrel hood to verify resized case length.

Going right to left in the above graphic with A) through D) representing left to right labeling:

D) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is too long and slide won't go into full battery as case rim protruding above barrel hood will prevent full lock up.

C) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is headspacing off chamber and slide will go into full battery as case rim flush with barrel hood will allow full lock up (As indicated in the graphic, this will allow better sealing of gas as case mouth seals with chamber wall and produce improved accuracy).

B) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is shorter than chamber to breech wall face distance and chambered round case rim can start to contact extractor to headspace off extractor (When powder is ignited, expansion of gas will push case rim against the breech wall face pushing case mouth away from the forward part of chamber, leaking more gas). If you use mixed range brass that's been reloaded multiple times, resized case length can vary quite a bit and neck tension/taper crimp amount could vary and addition of variance of gas leakage around case mouth all can tolerance stack to affect accuracy (Trimming case mouth to same resized length can improve flare/taper crimp amount consistency but won't improve gas leakage).

A) If dummy/test round drops in freely into chamber and spins without hitting the rifling, resized case length is so short that chambered round case rim is held back by extractor with case mouth dangling away from forward part of chamber to affect accuracy (It's like shooting 40S&W in 10mm barrel). When powder is ignited, expansion of gas will push case rim against the breech wall face pushing case mouth further away from forward part of chamber leaking more gas.


Another thing with using mixed range brass that can vary in resized case length; when I am setting up dies, I will measure resized case length of sample brass to identify "median/average" range of resized case lengths. When determining Max OAL, I will tend to use shorter resized case length as longer resized case length will allow less bullet nose/shoulder to protrude above the case mouth at the same OAL. (Using shorter resized case length to set flare/taper crimp amount will allow more flare/taper crimp with longer resized case lengths to help prevent shaved bullet, especially for seating/taper crimping in the same step, and skosh more taper crimp to not hang up flared case mouth with chamber wall).

If you are after utmost consistency, you can sort for same headstamp and same longer resized case length that will apply more consistent flare/taper crimp amount with more consistent finished OAL and more consistent neck tension/bullet setback - https://www.thehighroad.org/index.p...e-consistent-oal-on-progressive-press.921633/
Click to expand...
Thanks for all the advice and opinions!

I’ve decided to not trim 45acp nor 9mm cases as a routine.

I will use the Lee gizmo to chamfer cases as was my original intent.

I long ago began sorting by headstamp and because of suggestions here just a couple days ago sorted nearly all Winchester’s by case length. (See picture)

I have been loading only Winchester for a month or so and will now load only those greater than .892” or maybe .893” and thus will cull shorter ones and replace as necessary with longer.

I AM going to trim these:

While measuring and separating by length, I came across a large number of 45acp cases which were not “square” for lack of better term and the measurement changed as I turned the case. Not sure if that means the base is bent or the mouth is undulating or something else.

Anyway, I’m going to try and square them up. Why? I’m not real sure.

Pic shows most of my Winchester cases. .893 and over are in blue mtm boxes and baggies. Two containers stacked are .890-.892 and single container to right are .889 and below. Some way below. The latter will never again see the light of day but no I won’t trash them.

Dropping various length empty cases into barrel was an enlightening exercise. I wonder if I’ll be able to tell the difference in my shooting.
IMG_4304.jpeg
 
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GeoDudeFlorida said:
All these fellers talking about saving time and shortening the reloading process… like they got other things to more important or something. Meanwhile Ol’ Glenn’s looking for ways to spend more time with his brass and press. I gotta say, there’s something to be said for not needing or wanting to be in a hurry.
Life is just too short to be in a hurry.
Click to expand...
Wisdom from the tropics:)
 
I have a lot of range pickup and have separated cases by MFGR. I have found the MFGRs are pretty consistent in their case OL. However, that said there are slight differences in case OL between MFGRs. Hense separating the different MFGRs and set up dies appropriately for their differences. I did at one time stim all the cases to the smallest OL but it was easier to adjust the dies.
 
I’m probably writing this to myself but I tried out my Lee Quick Trim Deluxe this AM.

Works as advertised—pretty slick actually—but I won’t be using it much on my 45 ACP brass because while it’s doing a great job chamfering inside and out, it would quickly cut down the case length almost without you knowing it and trimming autopistol cases is not my goal.

But I took about 20 shorties (cases already under .888”) and trimmed them down to all sorts of shorter lengths quickly and expertly looking.

I think I see some custom made cases in my future—cut down from 45 Win Mag. All I need is another expenditure on a mini cut off saw. Thanks for the idea @Bcwitt
IMG_4308.jpeg
 
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