i few months back i got an o3-a3 and was all hot to trot with cast boolits. slugging the muzzle resulted in a disgusting big bore. i shot a few loads thru the gun and nothing was great. while looking for leading, i noticed a "hole" in the muzzle "star". it was low and right.....just where a right handed person would be stroking a cleaning rod.......i quit shooting, cleaned the gun and took a hacksaw to the bbl ! i cut about 3/8's off, refaced and crowned. i then tried some condom loads still thinking i had an oversized bore. i was shooting berger 175's..... this gun loves them.
i was contimplating using the hbc in this gun but not with the big bore.
just realized i had not re-slugged the muzzled after re-crowning.....duh.
ok the good news,,,,it is .309 x .309......yeah !
back in biz with the hbc and whatever else i have left in the mould line.