I contacted RCBS recently because I couldn't find any published specs on their full-length sizing die neck diameters. They were kind enough to provide the following info:
6.5 Creedmoor .283 +- .002"
270 Winchester .298 +- .002"
7mm-08 .303 +- .002"
I was surprised RCBS does not hold them to tighter tolerances. I want to try using them without an expander and a .004" swing could make a significant difference on neck tension. There is a set of pin gauges on Amazon for $120, but that's alot of $$$ for an old retired guy. I know Forster will hone to tight tolerances, but I already have these RCBS dies.
I have a caliper and a ball micrometer, but no inside micrometer.
I thought maybe I could size brass without the expander ball and subtract .001" for springback. Would that give me a close estimate of the die's neck diameter?
6.5 Creedmoor .283 +- .002"
270 Winchester .298 +- .002"
7mm-08 .303 +- .002"
I was surprised RCBS does not hold them to tighter tolerances. I want to try using them without an expander and a .004" swing could make a significant difference on neck tension. There is a set of pin gauges on Amazon for $120, but that's alot of $$$ for an old retired guy. I know Forster will hone to tight tolerances, but I already have these RCBS dies.
I have a caliper and a ball micrometer, but no inside micrometer.
I thought maybe I could size brass without the expander ball and subtract .001" for springback. Would that give me a close estimate of the die's neck diameter?