Why not try the 6CM, 107GR. SMK @ up to 3200fps, no turn neck, very seldom need to trim necks, and barrel life of over 4000 rounds with slow burning powders like H-1000 and H-4831SC. Super accurate and flat shooting with the 107's and 115 gr. bullets, and less wind drift than the 6.5 x 284. Rounds are made by fire forming standard 243 loads using the slow burning powders, the fire forming loads shoot as accurately as the fire formed loads, just a little slower. I imagine it would push the lighter bullets real fast if speed is what you want.