Most of us have never mistaken Sylvester Stallone for a cutup. Maybe the occasional producer has — the makers of “Rhinestone,” say, or of “Stop! Or My Mom Will Shoot” — but not the rest of us. So it’s a surprise that Stallone is as funny as he is playing a hit man paired with a cop in “Bullet to the Head.” He’s man-cave witty in a way that his “Expendables” movies have strived for but haven’t really managed. If “Bullet” had anything else going for it, it might be a little more than just the grungy revenge flick of the week.

Stallone pulls off his trick by not trying too hard, by not mugging. His New Orleans mob palooka, Jimmy Bobo, generally looks annoyed to be here, or bored at the very least. He’s a guy who brings his own whiskey to bars and churlishly “rents” a glass because he’s got no patience for his obscure label not being stocked. (The one thing he does have patience for, seemingly, is marathon tattoo sessions; the sprawling canvas of faux ink Stallone flashes makes that weird, veiny, sexagenarian-bodybuilder’s torso look that much funkier.)