Trimming revolver brass

...some case mouths barely crimped at all, while others rolled clear up under the crimping ledge in the die and distorted when I forced the ram through its stroke.
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I'd take a serious look at your seating die if I were you. Straight wall cases that are a couple of thousand shorter or longer just don't do that. I've been reloading for 40 years without trimming handgun cases and never have seen anything like you just described.

Don
 
I've been reloading for 40 years without trimming handgun cases and never have seen anything like you just described.
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Loading revolver ammo with a roll crimp is the relevant experience here. 40 years of 9mm, 40 S&W, and 45 ACP wont' tell you much.

As far as precision, I have been working with a nominal length +-.003. A case that falls within that range does not get trimmed. It could probably be more generous. Cases vary more than that, and thus the trimming.

I also have a 19-4 that likes brass that is .010 shorter than what will run in my other guns. I have to measure everything to keep them sorted.
 
FWIW, one time long ago I measured about 40, mixed mfg., a few times reloaded 44 Magnum cases. The length difference hovered around .005" (.004 +/- .002"), which had no visible/measurable effect on crimp (Redding profile and RCBS roll crimp dies). Velocities didn't vary more than with new, trimmed brass, and accuracy was very close, the same. I understand that in theory consistent case lengths can make for consistent crimps, but in all my reloading for revolvers, made no difference. Not condemning trimming revolver brass, but just sharing my experiences to give a new reloader that may be following this thread all info....
 
I found significant variation in 357 Magnum and absolutely among 38 Special head stamps. This morning I checked my Starline 327 Federal Magnum, fired brass, and it grew a pretty consistent .008-.010 during sizing and cursory expansion, with only a handful that needed trimming to nominal from outside the +.003 range. That cartridge gives me the most gauging rejects, mitigated with a shorter COL (case length moving the crimp groove back).

I have not advocated anything but merely shared my experience and what I do in my reloading. I have no doubt that most untrimmed cases would work, but I have one revolver that is case length sensitive, needing to move the bullet back slightly relative to the crimp groove, and a 357 rifle that needs a COL under a maximum.

Note that Hornady does the same thing in order to get certain bullet profiles to function.
 
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I've been reloading for 40 years without trimming handgun cases and never have seen anything like you just described.

Loading revolver ammo with a roll crimp is the relevant experience here. 40 years of 9mm, 40 S&W, and 45 ACP wont' tell you much.
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Sorry, Real Gun, but I was referring to .38 Special, .357 Magnum, and .45 Colt, all of which use a roll crimp. Such a massive variance in results as you described over a few thousands shorter or longer case is indicative of something else going on either with your die or your procedure.

Don
 
Loading revolver ammo with a roll crimp is the relevant experience here.
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35 years here of 38, 357, 32swl; NEVER have trimmed a case, and have never needed to. Some folks like to make things more complicated than necessary because those practices carry over from rifle; understandable, but it is not necessary; and I just throw all of each cartridge in one big box. I don't bother to sort by headstamp either.

OH, the HORROR!..... :D
 
Sorry, Real Gun, but I was referring to .38 Special, .357 Magnum, and .45 Colt, all of which use a roll crimp. Such a massive variance in results as you described over a few thousands shorter or longer case is indicative of something else going on either with your die or your procedure.
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I never said anything about "massive", and I didn't say trimming brass was critical, although I did find that a couple guns need a shorter case, and some rounds will not gauge without more leeway in case length. Stock length of new brass doesn't always work. I trim cases because it moves me closer to perfection and craft in my reloading.
 
35 years here of 38, 357, 32swl; NEVER have trimmed a case, and have never needed to. Some folks like to make things more complicated than necessary because those practices carry over from rifle; understandable, but it is not necessary; and I just throw all of each cartridge in one big box. I don't bother to sort by headstamp either.

OH, the HORROR!.....
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Again, this thread is not meant to solicit your negative opinion about trimming brass nor is it promoting the practice. Take it or leave it. Some trim and some don't.
 
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As far as precision, I have been working with a nominal length +-.003. A case that falls within that range does not get trimmed. It could probably be more generous
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What I have experienced is that different brands of brass have different lengths no matter what SSAMI says about it.
I group my brass that needs roll crimped into 3 different categories of .010 in length each. I don't like trimming all my brass the same length because it seems like I trimming off needless length to make it all conform.
If you sort them to three length ranges of .010 difference and you keep them segregated, you will likely never have to trim them again.

I've noticed that I only seem to have to trim them one time and they seem to stay in the same range after that.
.010" length difference will crimp pretty consistently without driving you nuts.
I have some .357 mag brass that I haven't trimmed in years. But when I first got it I trimmed it into one of my three different length batches I use and it has stayed there ever since.
 
Real Gun, this is a nice interesting post you got going here. I've been reloading now for about 4 years and 6000 to 8000 rounds of ammo in 9mm 38, 357, and now 44 mag. I use a Lee terret 4 die press and I have never checked the case length but I do continually check the OAL. I reload because I can do it $6.00 /bx for the smaller stuff. I also stay pretty close to the lowest powder charges. I don't understand what you're trying to accomplish being so precise on case length when OAL can be affected by the depth of your bullet that will change the location of your crimp on a bullet as much as the length differences of your brass will. How much does the bullet depth change from load to load. I'm not being a smart allick, I'm just trying to learn as much as I can about reloading for accuracy. I realize I would want a more precise reloader if I were to start reloading for accuracy. There's way too much play in my Lee reloader to worry about .005 to.010 case lengths. I hope you don't mind me asking, but what are you trying to accomplish that requires such tight tolerances in the brass length.
 
Again, this thread is not meant to solicit your negative opinion about trimming brass not is it promoting the practice. Take it or leave it. Some trim and some don't.
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This is an internet discussion forum where even opposing viewpoints to the discussion are allowed. Some of us see zero merit to this practice and are saying so so others new to this think it is a mandatory necessity.
 
I trim my brass with the intent of getting a consistent crimp but have just discovered that the brass shrinks during firing and lengthens during sizing.
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Yep, but once it's done, you don't have to do it again and you have a consistent length for a standard crimp. It's a one time deal, the case returns to pretty much the same length after each sizing repetition. Rod
 
Yep, but once it's done, you don't have to do it again and you have a consistent length for a standard crimp. It's a one time deal, the case returns to pretty much the same length after each sizing repetition. Rod
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I expect that I would find that generally true, but I already know that I cannot check lengths before sizing and call it good, because there have been tolerance outliers after sizing of previously trimmed brass. I may not have to trim everything more than once, but I will have to on the few rogues and will have to keep checking length after sizing. I don't doubt the ammo would work without all that but would not be the quality and confidence level I want. Basically, I try for ammo at least as good and as pretty as new boxed ammo. So there will be those who don't tumble for looks either. It's my preference and does relate to function more than just being anal about it all.
 
Or it can be real simple in reference to straight wall rimmed cartridges, i.e. magnum rounds. Use the Lee collet crimper, much less sensitive to variances in brass length and easier on the brass as well. Even though they aren't listed for all cartridges, for a nominal fee they will make one for you, such as a .41 mag in my case.
 
If memory holds, have had pistol brass fired through a lever lengthen, as compared to same batch of brass and load fired from a revolver. That my be related to specific firearm/load, but remember it happening. And yes I am familiar with most semi auto pistol brass getting shorter with repeated use, and why.

If picking up others revolver brass, and I do when they leave it, am careful to segregate it by headstamp. Am also careful to check oal of brass. Am not mixing headstamps when reloading for accuracy.

I once trimmed a lot of 45 acp and 9mm brass, back when I could shoot well enough to notice a small improvement in doing so. Never did it again.
 
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