For factory ammo, I prefer the Winchester Supreme 180gr Accubonds or the Elite XP3's. I reload my 300WM since 2005 with the 180gr AB's, but have used the factory previously and my hunting buddies that shoot 300WM with factory loads prefer the 2 listed.

Reloads with RL22 with 215 primers works great for me!

Have fun on the elk hunt with your dad !!