Ackman
Gold $$ Contributor
My 6BR is 24" long, 14 twist and 0 freebore.. Best loads are AA2230 powder during load workup......58 VMax@3855 (3shots .150").... 55 Blitzking@3919 (3 shots .120"). That barrel cut to 20", I'd estimate maybe 100fps less velocity. Just a guess, your guess may be better than mine.
Those 58's are my pd and chuck load. Very effective.
Those 58's are my pd and chuck load. Very effective.