Went to the range yesterday to chrono some .45ACP loads. Also took some .45 Colt loads that I had loaded several months ago. As the title says, some of the .45 Colt loads wouldn't chamber in a Ruger SST Bisley that had been modified from .44 Mag to .45 Colt by David Clement who rebored the cylinder and fitted a new barrel. Some would chamber, with finger pressure, enough to allow the cylinder to turn. Some had to be removed.
This morning I got out several .45's and plug gaged the chambers:
Clement .45 Colt .480 gage enters(barely), .478 full chamber. .479 might but I don't have that size.
Ruger Bisley .45 Colt .483
Ruger Bisley .45 Colt SST .482
Freedom Arms .454 Casull .478 enters, .477 full chamber
" .45 Colt Cylinder .482 full chamber
" .45 ACP Cylinder .476 enters, .474 full chamber
" .45 Win Mag (JRH rechamber of .45 ACP cylinder) .480 enters(≈.45 ACP depth) .474 full chamber. ??
Rounds loaded w/.45-270-SAA measured .4738-.4744 just behind the crimp and .4750-.4758 at the base.
BTW, all loaded rounds dropped right into a Midway case gage.
A fired case measured .474 at the mouth and .4765 at the base.
I'm completely out of my comfort zone here and all these measurements may be confusing to some besides me. I really don't know what to think since the Clement gun seems to have the most consistently machined cylinder and the tightest. If I want my reloads to fit this gun, I'm apparently going to have to size smaller. ??
Any thoughts would be appreciated.