I didn't think the 8x57mm was ever was in BP. Point well taken about the larger bulelrts probably being too large for the chamber's neck diameter. My 9.3 x57 is just that way. It has an oversize groove diameter, a full .370". That largest bullet I can use are the swaged .375" Hornady's down to .367". Normal factory bulelts in 9.3 are .3650" to .366" depending on make (of those I measured).
: I have a 16 bore hammer double Husky w/ 2 1/2" chambers coming in the mail - probably be sent tomorrow. Right tube is straight rifled and the gun has a rear sight. I'm anxiously awaiting it's arrival.
ps- already have a 16 bore ball mould - HA!