Quote History Quoted:
7.62x51mm I presume?
A lot of the surplus 7.62x51mm Lake City NATO brass has been fired through machine guns and stretched because of it. MG's have loose chambers, longish headspace and are violently ejected causing resizing problems.
Turn your die down even more. Use heavier lube on the case body, none on the shoulder. Sometimes people mix brands of shell holders and dies which can cause tolerance stacking. Your die should be turned close to 1/2" past just touching the shell holder. This will allow the press to cam over getting every bit of slop out of the mechanism.
If all else fails you can remove metal from the top of the shell holder.
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This was an issue way back in the day with M60s which did not allow an easy headspace adjustment.
But it was never the major issue with using surplus 7.62mm NATO brass in a .308 Winchester chamber, so let's put this BS to bed right now.
The external dimensions of both .308 Win and 7.62x51mm NATO cartridges are exactly the same, however the chamber dimensions are significantly different, and not in a friendly .223 vs 5.56x45mm NATO way. The datum point on the shoulder of the 7.62x51 NATO chamber is .013" farther forward than it is on a .308 Winchester chamber, which means sports fans, that a 7.62 NATO or .308 Win round fired in any 7.62 NATO chamber is going to stretch .013" more than it would in a .308 Win chamber.
Consequently, when reloading military fired brass, you can expect to have to bump the shoulder back.