We have shot elk with my .300RUM with:
180 Rem PSP (factory ammo)
180 NP (factory ammo)
180 Swift Scirocco (factory ammo-not impressed at all)
175 Barnes LRX @ 3350
175 SMK @ 2950 (reduced load for my daughter)
210 VLD (both H & T) @ 2950 or 3100
210 SMK @ 3100
215 Hyb @ 3100
230 Hyb @ 3113 (current load)
The 210-230s are magic for a 1:10" twist. If you want to squeeze every bit out of the .300RUM, the 230 or a fast twist w. 245s is the way to go for LR game crushing power.
I think the RUM was born to run the heavies. If you want to shoot a 180-190, a .30-06 or .300WM will do just as good.