here i am loading some 223 bolt gun. i checked to sure that i had the die set correctly . i sized a case and slipped the brass into the chamber , needed just a bit more force on the bolt handle than it should take . then adjusted the die for perfect fit . removed and measured the brass and slipped it into an AR carefully closing .worked as it should . removed the brass, remeasured it, was the same . put it back into chamber and dropped the bcg as hard as it would go . removed the brass and it had shortened .007