I like both calibers which makes the choice difficult. I currently hunt and shoot 300 yard targets with my old M77 270 and it performs flawlessly. Everything I have ever shot with it has died quickly. I have other rifles both larger and smaller calibers so it is not so much the caliber as it is the unique style of rifle that the Ruger RSI's are and the simplicity.
We are blessed with an abundance of prey animals but of course where you find prey you will also find predators. Coyotes have taken pets from both our neighbours in broad daylight in their own yards and this past winter we were finding a dead deer in our hay yards about once a week that I am fairly certain were killed by a cougar(s). Both of these predators are opportunists so we carry when we hike or travel on foot around our farm.
We have always had black bears around but to this point they have not caused us any problems at all however this spring we were visited for a little over a month by a boar Grizzly. It was cool getting pictures and seeing him but I do not think he really represents a significant threat as they travel a great deal.
So my thinking in the Ruger RSI (beyond the unique and new factor) was something relatively light and small(ish) and simple to throw over a shoulder when we are out and about the farm on foot.
My understanding of rifle calibers leads me to think that either the 257 or the 7x57 will make a large enough leak in a coyote or cougar as well as upset the appetite of a black bear. Neither caliber is at all suited for grizzly but as I mentioned I do not see that being a significant threat, although either caliber would be a heck of a lot better than throwing stones........
Anyone familiar with the availability of either caliber? If I were to buy one now would there be little chance of getting the opportunity to buy the other caliber in the future? The 7x57 is available locally but the 257 would be a mail order bride.
For some odd reason I like the "sound" of 275 Rigby better than the 7x57?? I understand the reason for the name difference. I remember as a young man reading the stories of Col. Jim Corbett and his maneating tiger/lion/leopard hunting and he referred to carrying a 275 Rigby although not intentionally for the big cats.
Regards,
Dave.