A 1:9 twist should be more than enough to stabilize the 212 Gr ELDM. More times than not, You can't pick one factory loading and expect a rifle to shoot it awesome. Try a different factory loading if you don't want to reload.
if you are going to reload, start by picking a bullet that you really want to use and go from there. Choose a proper powder and start testing.
it's hard to tell you what weight bullet to use without knowing your parameters. How far you will be shooting at targets or when it comes to it, game and what type of game.
