Just sharing my experience.
So I got my new mold for my 30-30.
Barely works for the 30-30 though.
Cast at .313, so sizing down to .310 is tight. Also the nose cast large at .303 which is the main problem, have to seat the bullet a little to deep to keep from cramming into the lands to far.
I have changed temps and alloy composition, makes no difference.
Might give these boolits a try in my M91 Mosin.
I think I'm going to get a Lyman 311041 and hope it cast at least .310