do you need to crimp on 30 carbine?

[duggaboy]

Well, I just got the dies for the 30 carbine and now I am thinkng to myself, do I need to crimp the case or whatever crimp means to secure the bullet enough to function well in the semi auto type mode? Is this the correct thinking? How about the garand? or the MIa?thanks , duggaboy

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[sigman2]

duggaboy,

The 30 carbine case should not be crimped. This cartridge headspaces on its case mouth. Crimping can cause excessive headspace.

You will have sufficent bullet tension unless your expander is oversize. Same goes for just about any "standard" caliber using jacketed bullets. Some of the big brutes (heavy recoilers like the big magnums) will probably benefit from a crimp.

Pay close attention to case length. Keep all cases between trim and max length.

What I do is expand the cases with just enough flare to start the bulets, 1/32" - 1/16". I then set my seating die crimper to just slightly touch the case... just enough to remove any flare.

There is no need to crimp bullets for the Garand or M1A.

[jimb16]

The seating die is a taper crimp die. You don't need any additional crimp

[Maury Krupp]

The seating die is a taper crimp die. You don't need any additional crimp

My Dillon/Redding .30Carb die set has separate seating and crimp dies.

That said, I agree no *additional* crimp is required (or desired).

Just "crimp" enough to remove any bell in the case mouth.

Maury

[duggaboy]

yeah, so I loaded 250 rounds last night, used the seating die from Redding, worked well, and I did note just a slight crimp, I think it was, maybe I imagined this, but shot well without problems this AM, thanks guys, duggaboy

[dukeofdata]

It is best practice to MEASURE the results of your reloading operations instead of "eyeballing" or guessing. The spec case mouth diameter is 0.336 inches. I expand (bell) the case mouth to 0.342 inches to seat the bullet and return the case mouth diameter to 0.334 inches after bullet seating. This is the same diameter I've measured on factory ammo for the cases I'm using.

[Sunray]

"...should not be crimped..." Should not be roll crimped.
Been loading .30 Carbine, .30-06 and .308(for a real semi'd M14) for about 30 years. Never used a crimp for any of 'em. Neck tension is enough as long as the brass is the right length. Full length resizing, every time, is required for any bottle necked case used in a semi-auto.