I have not chronographed it but 30 grains of 3031 behind a 320 grain cast bullet seems to produce about decent groups at 50 yards. Left and Right barrels are about 4 inches apart but shots from each barrel are tightly clustered to others from the same barrel. A new mold just arrived in teh mail - I expect it to throw 350 grain bullets when I get a cahnce to cast again.

43.5 grains of 3031 seemed to be ok with the 405 grain cast bullet too.

Oddly enough Hornady's 350 grain jacketed bullet was striking a foot lower than my cast lead loads. Not sure what that is all about - maybe a better bore seal with the cast lead loads.