L.C. 308 Brass problem

1st suggestion-Attempt to send brass back, while politely explaining problem that it ain't ready to load.
2nd suggestion-Use USSR's method, which sounds reasonable, for a limited number of cases for a series of trial loads. See if the brass lasts for your purposes. Have never tried USSR method, but have bought oversize 308 that required about 3/4 resizings in incremental steps using regular fl die and sb die. Unfortunately, the resized brass was only good for 1 full power load till incipient head separation.

Not all dies work the same on all types of brass with differing histories. Not all mg chambers are the same.
 
USSR said:
I've done that and learned what happens; brass web area is reduced and after resizing with a .308 die, brass fits chamber. This ain't rocket science.

Don
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Of course the web diameter is reduced. But the body diameter at the shoulder is typically reduced first.

Did you ever measure body diameters incrementally from shoulder to web for each tenths of an inch the 308 case goes into the 30-06 die?

Results will vary across all combinations of die and case, thanks to dimensional tolerances.

I couldn't get once fired M118 cases back into the milspec chamber they were fired in.
 
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Bart,

The thing you are missing is the length of a .308 case in relation to the length of a .30-06 case. When you put a .308 case into a .30-06 sizing die; the neck never makes any contact and the tapering upper portion of the .308 case is in the wide, lower portion of the .30-06 die and doesn't get resized. The only portion of the .308 case that gets resized is the web area, which is where the problem is. All I can say is it works.

Don
 
you can try Mr. Guffey's method of slipping a feeler gauge under the head in the shell holder, so it forces the whole case up by the thickness of the gauge. That gets it sized down that much more.
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This works and is what it looks like and you will need to trim the feeler gauge to fit and remove the decapping pin or you'll poke a hole in the shim . I've been able to get as much as a .011 shim under there . Remember though you will be setting the shoulders WAY back at the same time .
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Just for general information, all LC 7.62 Brass must be considered once fired in generous and sloppy chambered machine guns (M-60 and current equivalents), to ensure full-auto feed and firing. That is the only current military use of the cartridge. They are very difficult to size because the dimensions were "puffed" in loose chambers.
In certain rare instances you may find M-118 or WRA (old) brass only fired in M-14's, that will be easier to size.
Most Reloaders acquire this brass to shoot in their own auto loaders, which beat up brass. 600 yard MOA is not so big of a concern for these. If it is, get a bolt gun.
 
M118LR 7.62 NATO rounds aren't normally used in machine guns.

Sizing most rimless bottleneck cases too much can cause excessive case head clearance to the bolt face when fired.
 
USSR,

First, the good news:
I think you've come up with a really nifty technique that I've never heard of anywhere else. I intend to add it to my bag of tricks and recommend it to others as superior to using small base dies to size obstinate once-fired 7.62 machinegun brass. You are certainly right about that.

The bad news:
Bart is also correct. But I think that is probably the real secret behind why this technique works well.

So, before I go further, try this simple test. Take the decapping pin and expander out of your 30-06 die, turn it upside down and drop a .308 case in. Since the height of a shell holder deck is 1/8" above a case head, if the case shoulder stops against the die before the head is within 1/8" of the sizing die mouth, then it is running into the sides of the die.

I tried that with my Redding .30-06 FL die. First, with a fired Remington .308 Win case. Its shoulder stopped against the body taper of the .30-06 FL die with the head sticking out 0.9" beyond the die mouth. I then dropped in a brand new piece of Lapua .308 Win brass, and it stopped with the head sticking out a little over 0.6 inches. So, neither got anywhere near to having 1/8" or less sticking out. This means forcing those cases deeper into the die will narrow them to conform to the .30-06 body taper. The taper difference is gradual, so you will hardly notice the extra sizing effort it causes.

But there is good news in that. The reason a fattened 7.62 case won't resize down enough in a .308 Win FL die is that it is so much wider than a .308 sizing die that it has too much residual spring and pops back out too much after resizing; sometimes still too much larger to chamber in a rifle. By narrowing fat 7.62 cases in the .30-06 die, you succeed in eliminating the excessive diameter and then a little. It will spring out from the .30-06 size, too, but not enough to get back to .308 size, actually leaving it narrower than the .308 die is up much of the body and at the shoulder. If the shoulder is moved too far forward for your rifle's chamber by sizing this way, then you just run it through your .308 die one more time, and you would be good to go. That re-run through the .308 die will set the shoulder datum location while re-expanding the sides slightly. But because the sides start out narrower than the die rather than larger, this time they will spring inward upon withdrawal instead of outward. No doubt that makes the case easy to chamber. And, of course, despite being a little loose, it will fireform to your chamber at the next firing and never need either the .30-06 die or a .308 small base die again.
 
I like this 30-06 die idea . I use LC brass A LOT and although at times I've needed a small base die . I've never needed anything more then that . I do like the idea that if my small base dies don't work there's another method to fix the problem rather then scrapping the brass .
 
Nick,

Thanks for taking the time to test this. I think it bears repeating that after you have reduced the web area of the case with the .30-06 die, you must follow up by running the case thru a .308 resizing die to fully resize it.

Don
 
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