15 to 16 grains of 4227 with a bullet that fits is as accurate as any 30-30 I have. I had Tom at Accurate molds make a custom mold for me that fits Marlin throats very well. I believe it is the 31-180R but don[t hold me to that. I'm not at home and can't check. For a production mold the Saeco 315 is an excellent generic bullet. I believe the 315 number to be correct. The Lyman 311467 (?) should work as well.
Good Luck,
Rick
