I shoot 350gr Hardcast bullets, Accurately, with the MG and 1-38 twist, my pet 350gr bullet is the Ranch Dog, I do not use tumble lube, I do pan lube those bullets. The Ranch Dog 350 shoots excelent! there is one other thing you need to be aware of with Marlins in 444, and that is fill the throat, thats why bore ride bullets seem to work great and why Ranch Dogs bullets shoot so great when they are at least .432.