Home Forums Hunting & Shooting Hunting Rifles Headspace issues w/ a belted mag?

"Belted magnum cases in 7 mm Rem. Mag. caliber have the potential for truly extreme stretching. A review of the SAAMI specifications for 7 mm Rem. Mag. and chamber measurements to the datum of the shoulder shows that, in the worst case, a minimum-length cartridge fired in a maximum-- length chamber could stretch by 0.0198". Rarely does one encounter a situation this severe, but if the shoulder is pushed back to the original datum point when the case is re-sized, stretching will continue with subsequent loadings. Cases showing signs of incipient separation must be discarded. Use of a tool such as the RCBS Precision Mic to measure actual headspace, will permit accurate die adjustment with no fuss."

In reloading fired brass for my .300 Win Mag and .375 H&H, I just neck size it with a Lee collet die. The cartridge then headspaces on both the belt and the shoulder. I haven't had any case head separation problems. I get 4-5 firings out of each case and then discard it.

"If,might,mebbe,woulda,coulda,shoulda"? Them ain't exacting standards.

[bleep] is only as difficult as a guy makes it.

Guessing can be readily eliminated and that's the route I prefer to travel..............

Belted or Non pushin' shoulders back is gonna cause stretching and bad juju. headspace to the shoulder and drive tacks.

As well as negating seperation issues and increasing relative brass life..............

I think we've established a base line on the mentality of such individuals. Idiots never win. Ever.

Chuck

If you don't know how to properly size brass, you might could have problems with case head seperation, matters not whether the case is beleted, rimless, rebated, rimmed. Just as a belt makes no difference to keeping ones trousers up if a big belly is driving em down.

I might could suppose several hundred thousand 7mm, 300 and 338 mags over 50 odd years that have been successfully reloaded kinda proves the point that it can be done, and on the other hand, some folks simply won't learn to do so no matter how hard one trys to teach em. Can't teach a stubborn mule any tricks.

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after the first firing I ALWAYS headspace on the shoulder .. [/quote]

That's fine when reloading. I'm talking about chambering and installing a barrel.

You are talking about building a rifle to spec, we are talking about brass life and incipient case seperations, which puts this discussion into the realm of handloading.

All of my belted mags headspace on the shoulder, subsequent to the initial firing. I do not let the RCBS FL dies touch the shoulder.

[quote All of my belted mags headspace on the shoulder, subsequent to the initial firing. I do not let the RCBS FL dies touch the shoulder. [/quote]
Idaho Shooter:
I understand what you're talking about.

I will not dispute that all of YOUR belted Mags, can be effectively head spaced on the shoulder.

However, in the case of a sloppy, chamber, as in �a bit wide at the shoulder�, this is not possible. By the time your FL die even finishes sizing the neck, the shoulder is squeezed/sized, and the shoulder is pushed forward. The case will not chamber until the case is fully sized, all the way in the FL die, and maybe some more, because that�s what it takes to push the shoulder back again. You then take what you got, good or bad, as far as how far the shoulder is from the end of the chamber.

In the above situation, forget everything you�ve heard about handloading belted cases, i.e. Partial FL Resizing, bumping the shoulder only .001 to .002, sizing for felt resistance when chambering etc. It just don�t work, hardly at all.

Smitty of the North