R: The Roberts is a great cartridge,and I'm sure it will do well on your mule deer hunt.
For the elk, there are a host of other cartridges that squeeze in between the 7RM and the Roberts,toss heavier bullets of greater diameter than the Roberts,yet bounce gently enough that your shoulder will not be bothered, but that is a personal thing that you have to determine for yourself.Among them may be such good things as a 260 Rem, 6.5x55,6.5 Creedmoor,7/08,7x57,etc....maybe even a 270 or 280,though both burn a skosh more powder and recoil a bit more than the others.All are elk capable.
Sounds to me like you may be a perfect candidate for 7x57 and a top shelf 140 gr bullet for that elk hunt!
