I have hunted wolves, and been out Doggin for a lot of people. The outfitter I used to work for used to tell the hunters "no less than a 150 grain..." 'cause they aint gonna stand there 20 m away and let you shoot'em. We hope to have people use their standard deer rifle. Big hole = down fast(humane and less work for us). I know you'll poke a big hole in the hide, but the trappers are real close (20 feet or less) when they shoot them in the head. If you see one, it'll be moving, and quite likely far away.
We've had hunters come up with 22-250, and 25-06 and I'd say unless you're a good shot, go bigger. Those hunters had broadside shots at 120m or so, and we chased two wounded animals for a few km (on snowshoes)before we lost them.
As for calling, I'm trying to call wolves on distress calls and coyote howls right now, and it's real hard. Wolves cover soooo much area that even if there are wolves in your hunting area often, you likely won't be in the right place at the right time, unless you're baiting, and that's a pile of work.
Good luck, and please don't try to shoot a wolf with a .22lr.
D