I started trimming some of my new Starline 357 magnum brass in order to get more uniform crimps when loading hot loads for my 4" GP100. Lets say 12.5 gr. 2400 under a Cast Performance 180gr. WNFPGC. SAAMI says brass length should be 1.290 - .020 or (1.290 to 1.270). I had to settle for a trim length of 1.275 simply because that is what the trimmer I have seems to like. I have a few that have come out as short as 1.268. That concerns me. I am tempted to chunk the short ones. I have looked through all my manuals at recommended trim lengths and the shortest I came across was 1.270. Most were 1.280 What do you guys think? Could this cause problems or am I being overly concerned. I try to be as safe as possible with my reloading process. I just do not have enough experience at this point to make a safe decision so I figured I would ask about it before I threw the short brass away.
What is to short?
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357 Magnum is the only brass I've ever trimmed (I only load for handguns). And like you, I did/do it for crimp uniformity.
I have Remington, Winchester, and Starline 357 brass that I bought new (and it's brass brass - not nickel). The Remington's run 1.280 to 1.283 (I checked a large group of them - not all of them); so I left them be. The Starline's run 1.276 to 1.280; so I left them be. BUT - I keep them segregated from each-other. The Winchesters were all over the place and I trimmed them to 1.275. A good % of them were shorter than 1.275, and that's okay - they weren't too much shorter - like 1.268-ish, etc. And that's just fine. I prefer to stay within SAAMI spec, but a couple thousandths below the 1.270 isn't going to make enough difference. Plus, I don't build hot-rod ammo; so that gives me a some wiggle room.
A variance of even 10-thousandths isn't enough to make any real difference IMO. Also, all my "range brass" 357 (which IS nickel plated) is trimmed to 1.275 - as applicable. Again, if it's shorter, I just left them be. Basically, if you just trim down the long ones, the remainder will be okay if they're a few thousandths shorter. Makes sense?
Remember: If you trim, chamfer and deburr.
I have Remington, Winchester, and Starline 357 brass that I bought new (and it's brass brass - not nickel). The Remington's run 1.280 to 1.283 (I checked a large group of them - not all of them); so I left them be. The Starline's run 1.276 to 1.280; so I left them be. BUT - I keep them segregated from each-other. The Winchesters were all over the place and I trimmed them to 1.275. A good % of them were shorter than 1.275, and that's okay - they weren't too much shorter - like 1.268-ish, etc. And that's just fine. I prefer to stay within SAAMI spec, but a couple thousandths below the 1.270 isn't going to make enough difference. Plus, I don't build hot-rod ammo; so that gives me a some wiggle room.
A variance of even 10-thousandths isn't enough to make any real difference IMO. Also, all my "range brass" 357 (which IS nickel plated) is trimmed to 1.275 - as applicable. Again, if it's shorter, I just left them be. Basically, if you just trim down the long ones, the remainder will be okay if they're a few thousandths shorter. Makes sense?
Remember: If you trim, chamfer and deburr.
I don't measure my revolver cases. I set my "seating die" to give a proper roll crimp with the proper OAL for the bullet I am using. This places the crimp into the cannelure. If the case is too short, there will not be a crimp and that round is then broken down, and the components reused and the case tossed.
So the answer is, "if you can not get a crimp on the case, yes it is too short!" and toss the case.
Jim
Forget SAAMI dimensions. They're for manufacturers not reloading.
The trim-to for .357, if you ever need to trim in the first place, is 1.285". Max case length is 1.290". Anywhere in between will do. However, 10 thou isn't a great deal. It'll do. Your OAL will need a bit of adjusting, but nothing bad will happen.
What the trimmer you have likes is irrelevant. You trim to a specific length.
"...or even a .38 S&W case..." Isn't just a short Special or Magnum.
The trim-to for .357, if you ever need to trim in the first place, is 1.285". Max case length is 1.290". Anywhere in between will do. However, 10 thou isn't a great deal. It'll do. Your OAL will need a bit of adjusting, but nothing bad will happen.
What the trimmer you have likes is irrelevant. You trim to a specific length.
"...or even a .38 S&W case..." Isn't just a short Special or Magnum.
That is my plan exactly 1100 tac. T. O'Heir, thanks for the response. Likes was a euphemism for, "the only length it will trim" lol. I have that problem solved thanks to Lee CS....
I use SAAMI specs as a guide and for general safety but to each his own. Thanks again for the responses.
I use SAAMI specs as a guide and for general safety but to each his own. Thanks again for the responses.
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