That is only true if you use the ammo in only the rifle that you shot it out of .. But if you reload your ammo alot you should use the full sizing die because that way you know that the ammo will fit and feed with no problems.. Also if you are reloading belted mag's or any other cases you should trim to size all of the cases.. you can get the trim info online or maybe one of us have your info for you.. Be safe and good luck.. Retired USMC Sniper, LM NRA, LM National Match Shooter ASSC..
