... they use both .311 and .312" diameter and pretty much sez what ya'll do. The barrels vary and slugging/experiment is the way to go.
Thanks!
PS I really like this. It's a great shooter and I love the open v-notch sights that enable me to see the target well rather than squinting through a peep.
PPS. Silly me. I've got some factory PPU ammo that I know shoots ok. Why don't I just measure that for starters???
PPPS It seems that most factory ammo has .312" dia bullets. That's probably a good starting plac.