If your deciding between 7x57 or 7RM. Then 7RM no contest. But I would seriously consider a 7-08 over your two choice's.
If you reload I'd go 7mm Rem Mag because you can load it down to 7x57 ballistics if you want but you can't load a 7x57 to 7mm Rem Mag ballistics, seems a no brainer.
Nothing wrong with a 7X57 as it has more than enough punch for big animals. Not 100% sure, but I believe that was Karamojo Bell's "go-to" gun for African game, including elephant. I have a preference for its parent 8mm.
But, between the two options, I would go with the 7mmRemMag just for the ease of buying ammo off the shelf.
I think 6.5X55 would be a great for both Elk and Whitetail
I'd go for a 7mm Rem Mag.
Load it down a bit for deer and choose a slightly lighter bullet.
Load it hotter for elk with a tougher/heavier bullet.
Also the gun is for mixed bag hunting, encountering both species is likely and both tags are available over the counter. Maybe I will play with 200-225's in the .338 wm.
I was thinking of something in the 150 grain area in the 7mm mag or 175 grain woodleighs in the 7x57.




























