Like the amped up comeback tour of two rockers who had their heyday sometime in the mid-’80s, Sylvester Stallone and director Walter Hill (“48 HRS.,” “The Warriors”) join forces for a hard-hitting exercise in beefy, brainless fun with the actioner “Bullet to the Head.”

Taking its B-grade scenario la lettre, this assassin-cop buddy movie aims to accomplish little more than delivering tons of kinetic wham-bam fight sequences and LOL one-liners, which Stallone recites from a face that seems literally frozen in time. Independently financed, “Bullet” should target decent crowds, especially abroad, though will play best on the small screen.

Adapted by Alessandro Camon (“The Messenger”) from the French comic book series by Matz, the film shifts the setting from New York to New Orleans (tax credits, anyone?), though that location is never officially named – and, like many things in this fast and easy shoot ’em up, such details don’t really matter.

An opening assassination scene, replete with a prostitute and lots of cocaine, introduces us to Jimmy Bobo (Stallone), a tired and heavily tattooed hit man who’s seen it all but still can pack a nasty punch. When Jimmy’s partner (Jon Seda) gets sliced up by a muscle-bound meathead (Jason Momoa) with expert mercenary skills, Jimmy vows revenge. He teams with an out-of-town detective, Taylor Kwon (“Sung Kang,” “Fast Five”), who’s been sent to investigate the murder of his former partner – who turns out to be the very man Jimmy took down.

If this sounds complicated, it isn’t, and once those major plot points are dispatched with, “Bullet to the Head” dishes out 90 minutes of old-school mayhem, accompanied by plenty of comic banter between the aging thug and his Korean protege. It’s as if Stallone and Kang were swapped in for Nick Nolte and Eddie Murphy in yet another “Another 48 HRS.,” with Bobo showing Kwon the ropes while insulting his ethnic origins, even if it’s clear we’re in bromance territory from the get-go.

After much face smashing, the two renegades eventually catch wind of a local conspiracy involving government contracts, converted condos and Christian Slater, who makes a fun cameo as a local sleazeball with a few zingers of his own. As is required in this sort of nuts-and-bolts material, all the characters wind up at an abandoned power plant, where the big showdown goes down with bullets and battleaxes and some more jokes from the peanut gallery.

We’re clearly in “Expendables” territory here, though unlike those rather drawn-out affairs, Hill keeps his movie lean and mean, cutting straight to the punch lines while administering violence in quick and crunching doses. Bobo refers more than once to his old age, but Stallone can still throw himself into a good fight (courtesy of stunt coordinator JJ Perry), though he’s more convincing kicking butt or dropping one-liners than when he’s garbling a voice-over.

The Louisiana-shot production doesn’t exactly do justice to its purported $55 million budget. But the locations are colorful and well-utilized, and the hard rock score by Steve Mazzaro fits this joyride perfectly.