I just put 100 rounds through my new .308 (custom build with a Krieger barrel)... they were all hand loads with brand new Lapua Brass.
I measured a little less than half the cases, to figure out the correct headspace for this rifle... the longest measurement I got (head to datum line) was 1.620 inches (only two cases were this long). About half of the rest measured 1.618 inches and about half measured 1.617 inches (with a couple measuring at 1.619 inches as well).
First question:
Logic tells me that I should be working off the LONGEST measurement that I got from my fire-formed cases (1.620 inches), when determining my final case size... bump the shoulder back .003 inches from 1.620 to 1.617... even though the majority of my cases measured at that length already. Am I assuming right?
Second, third, and fourth questions:
I put one of the cases that measured 1.620 inches in my press and full-length sized it. The first time I sized it I had the die backed out a little bit because I didn't want to oversize it and make it too small. That case measured out to 1.623 inches after being full-length sized... it actually grew .003 inches. I screwed the die all the way to the shell holder and gave it an extra 1/8+ turn, to take all the slop out, then resized the case. This time it measured out to 1.621 inches.
Is it normal for the base to datum line (headspace) measurement to GROW after full length sizing?
Has anyone else encountered a chamber that is cut so small that a standard "off-the-shelf" sizing die will not provide the proper headspace?
Is there a good solution for my problem? MY rifle is telling me that it wants 1.617 inches of headspace, but my die won't give it to me, what can I do? ...grind the face of the shell holder down a bit maybe?
Any insight, advice, or suggestions would be greatly appreciated.
Thanks!
I measured a little less than half the cases, to figure out the correct headspace for this rifle... the longest measurement I got (head to datum line) was 1.620 inches (only two cases were this long). About half of the rest measured 1.618 inches and about half measured 1.617 inches (with a couple measuring at 1.619 inches as well).
First question:
Logic tells me that I should be working off the LONGEST measurement that I got from my fire-formed cases (1.620 inches), when determining my final case size... bump the shoulder back .003 inches from 1.620 to 1.617... even though the majority of my cases measured at that length already. Am I assuming right?
Second, third, and fourth questions:
I put one of the cases that measured 1.620 inches in my press and full-length sized it. The first time I sized it I had the die backed out a little bit because I didn't want to oversize it and make it too small. That case measured out to 1.623 inches after being full-length sized... it actually grew .003 inches. I screwed the die all the way to the shell holder and gave it an extra 1/8+ turn, to take all the slop out, then resized the case. This time it measured out to 1.621 inches.
Is it normal for the base to datum line (headspace) measurement to GROW after full length sizing?
Has anyone else encountered a chamber that is cut so small that a standard "off-the-shelf" sizing die will not provide the proper headspace?
Is there a good solution for my problem? MY rifle is telling me that it wants 1.617 inches of headspace, but my die won't give it to me, what can I do? ...grind the face of the shell holder down a bit maybe?
Any insight, advice, or suggestions would be greatly appreciated.
Thanks!