The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Is there a rule of thumb deciding on the optimal bullet size once you've slugged your barrel, ie what degree of oversize do you go for from the engagement of the rifling or is it a calculation between the difference of the measurement of the lands and grooves?

Tia

This is what I used to for my M44

http://7.62x54r.net/MosinID/MosinSlug.htm

Ideally you should size your bullets to fit the freebore, so long as such a round will chamber.