RE: New Gun!!
I believe you will find the 7mm Remington Magnum cartridge has all the power you will ever need for any animal you might run across in New Mexico, including the occasional grizzly you might encounter in the Pecos or Gila Wilderness! That 7 Mag. is an excellent elk cartridge! I use a handloaded 175-grain Nosler Partition in my Ruger No. 1B for elk, but a 160-grain is probably just as good. I found that mine destroyed a little too much meat for me when using it on deer (with the 140-grain bullet), so I got a 7X57mm for the "smaller" stuff, like the 300+ pound mulies you find in the Turkey Mountains near Ocate!
You are indeed fortunate to be able to hunt in NM! Good luck and enjoy!