The .300 win mag will do ya fine and be a excelent elk round.I would also tell you to look at the .338 win Mag,Federal offers a 210 gr Nosler that is GREAT elk med's.
I shoot the 180 gr Power-shok(federal) for elk out a my .300 Win Mag.It's only 13.00/box vs the 46.99/box for the 300 RUM Core-lok Ultra's.I will tell you the 300 RUM is a heck of a elk gun.
BBJ