Which detachable mag box have you guys been using on your 338 Normas. I was going to use the wyatts box that is made for the 338 Lapua that you can fit a round where the coal is 3.790. Is this too long for the Norma? Will I ever need to seat a bullet longer than that? Could I get away with the mag box that is 3.700? Want to shoot mainly 300 OTM or the new 250 OTM.