Up here on the Kenai Penn, I'm having good results with a plain Jane Winchester model 70 in 30'06. I have learned through first hand witness and first hand experience that while they can be killed with the various 22 centerfires, the best wolf gun is a trusted deer gun. They truly are a stout critter, once winter comes on. I mainly stay out of the shoulder, as I am hunting and trapping for pelts.
The semi auto rifle sounds like a good idea, but if you are very serious about wolves, that means snow. Wolves are slick and I like to set up in a manner where I'm only a slight head movement to acheiving good stock weld. They are very visually sharp. So I like to be right there on my gun. Borrowed a friend's 450 BM, and my face and hands were miserable! Wolves like to chase and hunt in the open....it's easy to get doubles with a bolt action rifle that you have history with.
KF hunter, I remember being castigated very badly and soundly in this forum last year for my interest in this caliber. While not popular just yet, sportsman's sells every rifle they stock. Mostly for wolves. *Soldotna
Most of my friends and my own wolf shooting is done at 200 to 300 yards.