Personally, I like authority on Elk, but either of your choices will work. Since you have chosen the 7 SAUM, I would be working on a good
160/162 grain load, and run with that. Unless you have enough magazine length and a deeper throat, 175's take up a fair bit of powder
space in that case. Believe it or not, Moose are generally easier to put down than are Elk. An Elk at 500 meters wants good bullet placement,
and enough residual speed to ensure expansion. My last Bull Elk was 425 yards, so shots can be longer at times. Dave.