All barrels are different. I've had solid performance from 150-180 grain bullets on elk. Bullets as "soft" as SGK's to as "tough" as Partitions. The best all-around bullet in my .300WM on elk has been 165 grain NAB. I push it out at an average of 3221 FPS with 71 grains of IMR 4350, lit off by a GM215M at a COAL of 3.345". This is out of a Kimber Montana w/26" tube (2010 model). Ranges on the elk ran 42 to 617 yards, a single shot for each. Enjoy the load development process, it too is part of the hunt.