A 7 mag is the only big game caliber I've ever hunted with. I've taken deer, antelope, elk, coyotes, ground squirrels, crows, jack rabbits, buffalo, and my daughter shot her moose with it. It's a great caliber. I have a Remington 700 with a custom stock. One of my favorite loads is 66 gr. of H-4831 with a 160 Speer. It's a litte hot but it shoots under an inch. I playing with some 139 gr Hornady's right now. I have them at 3/4" group right now with 4831 powder. I'm trying some reloader 19 in my next batch to see if I can get a little more speed get my groups smaller. I'm thinking of buying a 300 ultra mag and looked at the XCR. It's a nice rifle but the thing that turned me off was the CHEAP plastic stock Remington is putting on thier guns. I may just buy the SPS, its the same action and barrel but without the tryonite coating, and it has the same stock without the rubber overmolding , and it's about $200 cheaper coating, and have a custom stock built for it.
Wes