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mehavey · May 4, 2013, 09:39 AM

1. Case isn't crushed (if it's actually crushed) during resizing. It's crushed if/when the seating die's crimp ledge starts crimping into a non-cannelured bullet before the bullet is fully seated. When the crimped-bit bullet then moves down, the the case shoulder sides take gthe hit -- producing shoulder interference)

2. On the other hand, if the sizing die is left a scoch too far out, it squeezes the case sides in (lengthening the case/shoulder dimension) and the shoulder itself is left too long. (Headspace problem)

- OR -

3. That once-fired 308 brass is mil-surplus from a machine gun and might need to be small-base re-sized the first time out.

I'd proceed 1, 2, 3 in checking it out -- UNLESS a case right out of the re-sizing operation (no priming/no powder) won't chamber or chambers hard. Then it's #2 (likely) or 3 (less likely/but possible).

BREAK BREAK. My Model 70 has minimum headspace. Winchester brass requires that I go shell-holder contact +1/16 with the die to chamber. My Lapua brass (softer shoulder/annealing) requires only ordinary die contact. I have to set each up differently, using a Stoney Point headspace gauge to confirm 2.044" at start.

(Ain't this fun?)

May 4, 2013, 09:39 AM	#11
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,896	1. Case isn't crushed (if it's actually crushed) during resizing. It's crushed if/when the seating die's crimp ledge starts crimping into a non-cannelured bullet before the bullet is fully seated. When the crimped-bit bullet then moves down, the the case shoulder sides take gthe hit -- producing shoulder interference) 2. On the other hand, if the sizing die is left a scoch too far out, it squeezes the case sides in (lengthening the case/shoulder dimension) and the shoulder itself is left too long. (Headspace problem) - OR - 3. That once-fired 308 brass is mil-surplus from a machine gun and might need to be small-base re-sized the first time out. I'd proceed 1, 2, 3 in checking it out -- UNLESS a case right out of the re-sizing operation (no priming/no powder) won't chamber or chambers hard. Then it's #2 (likely) or 3 (less likely/but possible). BREAK BREAK. My Model 70 has minimum headspace. Winchester brass requires that I go shell-holder contact +1/16 with the die to chamber. My Lapua brass (softer shoulder/annealing) requires only ordinary die contact. I have to set each up differently, using a Stoney Point headspace gauge to confirm 2.044" at start. (Ain't this fun?) Last edited by mehavey; May 4, 2013 at 10:54 AM.