The Upper Green is a beautiful area. I usually ride into the Wind Rivers each summer. Green River Lakes, Elk Heart, New Fork, or up the Old Sweeny Pack trail. It's what I bought horses for.
I've seen Elk asorb two 180g bullets through the lungs out of 300WM another elk took bullets from a 30-06 and just stand and look at us. I've also watched them fold on the spot when hit with 120g partitions from my 25-06. Why one works better than another, I don't know. But they are all dead.
I watched a group of friends in Alaska shoot 7 bull moose over a 10 day period all with 140g Failsafe bullets out a 270 WSM. Not one moose was lost.
I may go back to a larger caliber gun if I find the 270WSM won't do the job. But for the time being, I'm going to try it. So far it's worked fine.
