Braden
Near Abilene, huh? I was stationed at Dyess AFB for 2 years and Daughter #1 is currently at Goodfellow AFB in San Angelo. Not much need for stainless down there! Here in Colorado the weather can be anything during elk season but my hunting rifles are all blued and Ive never had a problem the solution is called oil or wax.
As to most versatile caliber, thats a matter of opinion. A lot of people say that if you have a .30-06 you dont need anything else a very good reason not to have one, IMHO! Ive been hunting elk for 20+ years with a 7mm Rem Mag and Speer 160g Grand Slam bullets, never lost an animal or had one wander more than 50 yards after being hit, (My buddy neck shot one with that combo, and it went a little over 100 yards. Wasnt the fault of the bullet or the cartridge, though.) In all those years, I have recovered exactly ONE Grand Slam, meaning penetration has been complete on all the others whether at 100 yards or 350. I have also used the 7mm Mag for mule deer, antelope, coyote and even prairie dogs. With a 175g premium bullet, it should handle moose, but for big bears I would prefer a .300 or .338. Many people consider a .300 or .338 to be the best caliber for elk. If it were to do over with the knowledge and experience I have now, Id probably choose a .300 instead of a 7mm Mag. That said, a .270 with 150g bullets would have taken any elk Ive ever shot.
If you dont reload, Id suggest staying away from the WSMs. I think they will be around years from now, but ammunition costs are much higher than more established cartridges and they wont do anything that the standard cartridges cant do equally well. Most people are better off with less expensive ammo and more practice, IMHO.