54bore, unless your bore gets tighter on the way down, all bullets will seem a little easier from the middle down as the bullet shapes to the bore. Knurling may help a small bit in your case but more than likely not. My Renegade was a rare one. It is identical bore dimension all the way down. I have found no deviation whatsoever. You usually find it a little tighter or open on one side or the other. But even with concentric dimensions my full bore maxi balls feel a little easier after a few inches.