I ordered a Savage model 16 weather warrior 300 WSM last night, I'm gonna use Federal Fusion ammo for breaking in the barrel, does bullet weight really matter for breakin' in a barrel? I'll probably be using the 180 gr bullets.
Bullet weight will have no discernable impact on the break-in procedure. The primary purpose for break-in appears to dressing tool marks on the throat of the chamber. Hence, bullet weight is not a consideration.
