RE: 303 british ammo, and grain
Those should work well. I am sure they are legal in Sask. I don't know that for sure but one of the guys from there should be able to confirm that. I have hunted up there a lot and the guide I have used carried a 303 British all the time. I don't know what kind of ammo he used though. Can't imagine that it would not be legal. Good hunting.