Been loading for my 8 twist 300 Norma. Anytime I even approach normal loads and velocity I'm seeing serious pressure, ruining the brass in 2 firings. Could it be twist related ? I've been loading 225 ELD-M's over 81 grains of H1000 safely , getting 2900 fps initially, the same load is now clocking 2940 after 80 rounds fired . Never used an 8 twist .30 before and I was expecting to load a little higher charge and get similar velocity to what many others are achieving.