BehindBlueI's
Grandmaster
- Oct 3, 2012
- 25,905
- 113
Ahh ...
So essentially it's headspacing on the rim. I know nothing about revolvers, but in self-loaders, some cartridges were crappy performers in the accuracy department when the gun headspaced on the rim, but got a lot better when it headspaced on the case mouth (e.g. .38 Super).
I think perhaps the jump to the rifling. A guy on another forum tested 19 commercial loads and accuracy varied quite a bit for him. He's yet to publish which did best, though.