I don't load mine hot (anymore) and my throat has moved forward .043" after 600 rounds. The first huundread rounds were load development with the 142 SMK and H4350 up to 49 grains. After that it has had a steady load of 46 grains of H4350 and the 142 SMKs or 48 grains of H4350 with the 120 grain TSX.