I and my son in law use the Barnes 165 factory load out of my 300 WSM Kimber Montana. It's taken 17 elk, mainly bulls, so far.
With him using that rifle I'm now using an ULA in 300 WIN with the Barnes 165 factory load. I've taken one 6x6 at 450 yards.

The 165 Barnes are very accurate in both rifles and we are getting exits on broadside shots. Problem with elk as you don't always get that picture perfect chest shot so you need penetration and a tough bullet.