Jtplumb,
Not to get away from 9.3x72R but I noticed your comment about trouble with a 6.5x58R and Nosler or Barnes bullets. Did you "slug" your barrel or just assume it is .264"? Most 6.5x58R/6.5x48R or 6.5x70R are .260-.261", groove diameter. This may be the source of your problems. My own 6.5x58R has very shallow grooves, in addition to the small groove diameter. I often use oversize bullets in 9.3x72Rs, and 8x85I/IRs, but am very reluctant to do this with that particular 6.5x58R. I make my .261" by sizing .264". For this, you can't use solid or partition bullets as donors and must use "cup and core" type bullets.
Mike
