IT TAKES a brave man to pack a pistol in his pants and an even braver man to keep it loaded. "Cobra," latest in a growing legion of movie neanderthals, is so macho he plays Russian roulette with his masculinity, storing his Colt .45 automatic where most guys keep their figleafs.

Sylvester Stallone, Mr. Testosterone, plays the pistol- packing palooka Marion Cobretti, title role in this predictable new police adventure that cribs from Dirty Harry. Cobretti, a.k.a. Cobra, is a plainclothes cop specially trained to apprehend (and hopefully gun down) psychos, most of whom have been let back into society by wimp judges at the behest of bleeding heart journalists.

Cobra doesn't even read his newspaper; he just glances at it before he tosses it on the Weber grill. You've got to wonder why he doesn't just cancel his subscription. He also has a fashionable contempt for the judicial system, repealing the Miranda decision in his own inimitable way. "You have the right to remain silent," he advises a gasoline-soaked psycho right before he drops a match on him.

Cobra's love life, not active enough to turn off the 12-year-old boys, is cool by comparison, with Stallone inert opposite his off-screen wife Brigitte Nielsen as a high-fashion model who is menaced by an army of serial killers. Cobra's efforts at protecting her result in fast-paced mayhem, as he mows down a stampede of motorcycles with a submachine gun from the back of a pick-up truck.

The kill ratio is an all-time high as Cobra hunts down a covert cadre of the criminally insane, led by a Cro-Magnon killer with a weakness for hatchets. "Cobra," plotless and violent, though actually not all that graphic, is directed by George P. Cosmatos of "Rambo: First Blood" and written by Stallone. It's an action-packed but finally numbing assault on your nerve endings. It's orchestrated mayhem, with plenty of explosions, but no surprises.

You can say the same for "Rocky" and "Rambo," too. But they were just a couple of blockheads, numbskulls with big biceps and bigger obsessions. But Cobra is a detective, and detectives are supposed to be smart. Stallone's cop is just another ham-fisted hooligan, an unimaginative hero who hasn't got the smarts to solve a crime. Luckily, there's no mystery. The thing that keeps you guessing is that darn Colt. Is the Italian Stallion going to shoot himself in the foot? Or worse yet, become a gelding?

COBRA (R) -- At area theaters.