Yes I know bullet fit is king. But forcing cone angle degrees cylinder throats lube all play a rule. How hard the bullet is shape as a RNFP may enter the forcing cone better. Hardness of bullet being to hard will not grip rifling as good and therefore skid down the barrel. Yes I've used 2400 and 42227 both are great powders I came across 8 lbs of H110. Powder primer all of this comes into play that's what makes this reloading a great hobby for all.