M1 Garand and 311299

[6thtexas]

When loading 311299s (or any cast in a Garand) do y'all crimp them, merely take the tiny bit of flair out of the case mouth, or leave them alone? I got a NOE 311299 and cast up a bunch of bullets I hope to shoot soon in my old DCM Garand. This will be my first excursion into semi auto rifles with cast. I have read a LOT on here about loading for Garands but don't recall anything about crimping.

[georgerkahn]

Bion, I use Redding Dies for all 'cept the last step -- crimping -- for which I use the LEE FACTORY CRIMP DIE. Two notes, in a very friendly suggested fashion (I hope): 1. Make sure the powder you're using is OK for Garand loading -- I prefer IMR4895 for these boolits, which I also cast and shoot; and 2. Make certain none of your seated primers are proud to case head! Some friends just check their loads with fingernail to ascertain this; I'm too OCD and have a dial indicator on a holder to read actual primer depth. Knocking lots of wood (I'm superstitious) I've never experienced a slam fire -- and not only wish for me to keep it that way, but also hope the best for you! Every time one pulls the trigger, there's over fifty thousand pounds of pressure but inches from shooter's cheek!
geo

[lancem]

I just remove the flare myself.

[Outpost75]

If you just partially expand case mouths, so that the GC base rests solidly against an unexpanded "step" at the base of the neck, so as to positively prevent telescoping of bullets back into the case during the feed cycle, THEN you don't need to crimp other than enough to remove all mouth flare, and to ensure that loaded rounds will drop freely into and out of a Wilson Max. Cartridge Gage, to ensure safe feeding in your M1.
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When setting up to do this, I size cases in a Lee FL size die having a small diameter Universal decapping stem, and case mouths are inside deburred and separately expanded with an RCBS cast bullet neck expander with plug 0.002" under bullet diameter (.309" for .311" bullet) just enough to flare the case mouth slightly, to permit hand-starting the bullet to the top of the GC. I have "adjusted" the length of the cylindrical expander plug by stoning a lead-in taper in the drill press, so that the .309" cylindrical portion is no longer than the shank length of the bullet measured from crimp groove to top of the gas-check.

Push-test a sample of dummy rounds by first measuring overall length with a caliper, then holding the dummy rounds in a shell holder, push the bullet noses firmly against a bathroom scale with 50 pounds load for 5 seconds, then measure again. If rounds shorten more than 0.005" after the push-test you need the Factory Crimp.

[6thtexas]

Thanks for the help! I like the test with the scale. I was thinking how to check them.

[Scharfschuetze]

Outpost's method is certainly more refined than mine, but I just use a taper crimp die to take the flare off the lip of the neck. I've never had any problems doing this and I enjoy good accuracy with my M1 rifles doing so and reliability is fine. I might add that I use a custom made .308" expander and size my boolits to .311 depending on the mold and alloy. That gives me about .003" tension on the boolit which seems to be fine for holding the boolit during the round's ride from the clip into the chamber.

Your choice of the 311299 boolit is as good as it gets in the M1 if the nose diameter rides the lands as intended. My mold is actually a 314299, but it's just a smidgen larger in diameter than yours.

[Stoats]

If you've got some full diameter driving band outside of the case mouth, you can get away with harder crimping if you need it. This is simply because this bit cannot be sized down by the crimp, so provided it is over groove diameter, it will seal.

[varminter66]

I crimp mine to remove the bell, and then give it a little more, using the Lee Factory Crimp. Feeding has been very reliable, and accuracy continues to get better.