Every one that I've shot so far (I'm up to 4 now??) has been a "behind the ear" shot which resulted in DRT's. Two were with a 270 and two with a 7X57 Mauser. Biggest was a 350+ boar with the Mauser-he may have kicked a couple of times but never moved after that.
Carrying either a 308 Encore or the 270 now when I'm hunting them up here. I would love to take one with my smokepole but would only do that from a stand or have some real good backup if stillhunting them like I usually do.