getting a 12" single shot pistol in 308 win and was wondering if anyone has any bullet weight and powder combo's (not charge weight i'll work up ) that would work in that short of a barrel. i've been thinking about 130-150 gr. heads and know i should be going with a faster burning powder (use varget and rl-15 in my f class rifles) any ideas ? the pistol is a ssp91 rotory breach pistol my father had one in 357 mag years ago and it was nasty accurate.