Monday, October 01, 2018

Shrinkage

Brass, to be precise.  One thing I've noticed on making cases for that .310 is that the shrinkage after the first firing isn't real consistent; some lose very little length, some a LOT.

Last 25 cases we put together, after first firing most of them went from 1.140 to 1.130 inch; a couple stayed around 1.140, and one went to 1.125.  Previous results were similar on length lost.  That rifle seems to shoot best with 1.130 or 1.135, so I think next batch we do will start at 1.145(which is about the max length at which a round with the 120-grain RCBS bullet will chamber in it), so hopefully will wind up at the 1.135 mark.

No comments: