uneven case mouth

YoteAddiction

New member
Alright, I got my first 50 Winchester 7.62x39 Russian cases all full length sized, and ran them through the case trimmer, trimming them to 1.518 inches, measuring every five cases to make sure I was doing it right. When I got done I noticed that every case had one side that the trimmer didn't appear to have touched. The trimmed side measured 1.518 like it was supposed to, but taking several measurements spinning the case a little each time showed the untrimmed side measuring 1.514-.515. The trim to length for the case is 1.518. Its not a big difference, but aside from possible accuracy problems, the manuals also say that they wont crimp uniformly if the case mouth is uneven. Is this difference in size small enough to just run them as is, is it safe to trim them down a half a hair more to even them out, or is it a big enough difference to be a real problem?
 
It should be fine IMO. My lee zip trimer takes em down a lil short. Better a lil short than a lil long in case length. It will stretch back out anyway. as long as you got plenty of neck to hold the bulet it will be good. THe difference your talking about should be fine. Im not a crimper but ive never had issues with cases a few thousandths of an in too short.
 

All collet trimmers will have some wobble. If you want
square trimmed case mouths the Wilson trimmer is the only one
I know of that uses case holders, much like the rifle
chamber, and a hand lathe cutter head for square trimming.
Sinclair International has a really nice kit, using the
Wilson trimmer, providing a base stand, micrometer length
adjust, and a shark fin case holder clamp. Not the cheapest
tool, but a good value if square case mouths are the goal.

Squeeze
 
They are fine.

They will crimp fine, and shoot fine.

Meow
wink.gif
 
Not too keen on crimping. Do it if you feel you need to, but try a few without the crimp. See if the bullets move out in the cartridge. Probably won't. If you don't have to, don't crimp. It just works the brass more than needed. Oh yea, don't worry about the uneven lenght. You can square them up next time or just go back and cut them a little shorter.

Tom
 
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I was kind of hoping you guys would say that. It is just a tiny little amount, mostly I was just concerned about being able to crimp them.... which as mentioned may not even be necessary. The manuals I have kind of make it sound like a black hole will form and destroy the world if everything isn't perfect (I'm sure partly to stave off the lawyers, and partly to boost sales on fancy equipment) and since its my absolute first experience with loading I figured I would double check with some more experienced people before I proceeded with anything.
 
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