I have killed coyotes (here in the Adirondacks they can get quite large sometimes north of 70-80 pounds) with 16 gauge slugs, .22 Hornet, .32-20 and a car, but wolves are a bit bigger and I put them in the same class as some really large dogs. I would treat them the same.
Aggressive Dogs and Concealed Carry: An Unexpected Threat - Gun News at Guns.com