Quote Originally Posted by Shortbox4x4 View Post
It’s not just the brush but the hard carbon particles that can lay in the bristles of the brush. The hard carbon particles will scratch the bore more so than the brush. That being said if I use a brush I never pull it back over the crown.

Also you get a gas cutting effect when the bullet leaves the barrel. This alone after X amount of rounds can wear the crown. This is why I don’t like a flat/sharp crown edge. We cut a 60 degree chamfer on the edge of the bore. Feel this helps the crown hold up better overall. Ever look at a M1 Garand barrel? 1903? M14 and even on the Gov’t test barrel drawings they all call out a chamfer on the edge of the bore. Some where at some point in time someone figured out something here years ago!

Flat base bullets I’ll say are more forgiving then boat tails are but boat tail helps b.c.
Agree. Plus, it takes literally seconds when that piloted 60 degree center tool goes in and the setup is a snap.