I had a 200th year liberty model 77 ruger, chambered for 7x57mm. My wife bought it new for me in 1977 and I hunted with it for a few years. Later it went to my son and he has taken many deer with it for decades. We always loaded it with hornady 139 grain interlocks and they worked fine on deer. About 10 years ago, I found myself missing the cartridge, and so bought a ruger 1A, chambered for 7x57mm. I haven't fired it in years and can't comment on what it's capabilities, but the 1A is short and handy. I recently bought some 130 grain, .284 diameter speer boat tail bullets with the idea of shooting my 1A again, but haven't loaded any yet. The 130 grain bullets should be pretty flat shooting and might make a good deer bullet (deer, but not elk).
The Ruger #1, .275 Rigby (that you're considering) would be an elegant and classic rifle. As for the 7x57 cartridge, there's a thread going right now about deer camp rifles. It is surprising how many hunters are using the 7mm mauser cartridge. I suspect they represent an older and more experienced demographic. In any case, I can't remember seeing a used 7x57 sporting rifle on the used gun rack. People who own them are clearly keeping them. That being said, if I were starting from scratch and looking for a 7mm rifle, I would go with a 7mm-08. As for the .270 Winchester cartridge, I would look for a .280 Remington instead, but that's just a personal quirk of mine.
