My old MK-85 has deeper cut rifling (.008" I think where newer T/C'sare .005"). Really an exceptional barrel.

Which is better" Not much difference in my view other than the deeper rifling is a bit more fouling tolerant where the shallower button rifling in many of my other barrels require more frequent swabbing.

I swab after every shot anyway.

I'm sure that there is a more technical reply from someone here.

Button rifling is far less expensive and still yieldsa decentbore rifling.

Tahquamenon