With a scope, you can get 200 yds. out of it. I'd stick to 150 yds with iron sights.

I've killed several between 150 and 200 yds. with one shot, never counted the steps to be more specific than that.

if you can hit them in the vitals at 200 yds., it will work very well out to that range. if you can't, then you'll most likely kill him, but he'll run for miles first.