As I said in another thread, the .300rum is an excellent elk killer at 700 yards and beyond. Some of the admirable guys at some of the longrange hunting/shooting forums are getting elk at 1,500 yards with a .338 Lapua mag and even at that yardage, they are delivering 800 or so ft lbs, crashing thru any bone and dropping them.

Ive gotten two past 700 yards with my .300rum and Im still amazed at how potent it is.

I havent messed with a 7mm rum, but from the ballistics I just checked, its right there with the .300winmag. The only holding it back is the choice of factory ammo, and the weights of bullets isnt very heavy. If you reload, that problem goes away. Both offer great B.C. so shoot what youre comfortable with. At the end of the day, thats all that matters.