I phoned a Sask CO about the question. We than checked the Queens Printer about the wild life act and Sask Hunting Regulations. You can hunt in Sask with a pistol, as long as its not restricted.
So your rossi mares legs, Kriss, JR Carbines, and air pistols are legal...
How ever there is a caliber restriction for big game, and NO caliber restriction for upland bird.
We were not able to find a fps restriction, or any type of air rifle restriction. It only said it could not be a "spear".
So, who wants to bow hunt ducks? Lol, we had a laugh about the spear, i asked if i could use my air nailer than. Lol, he was a good guy and even was nice enough to return my call after talking to other employees about it. They all said they've never heard if it, didnt recomend it, but couldnt see how it was illegal.
Now thats a Sask Fish cop i called, check the queens printer for your provinces Wild Life Act.