SYLVESTER STALLONE stakes his claim to John Wayne's combat boots in the blood-and-guts, post war adventure "Rambo II." It's a crowd-pleaser if you're a serious reactionary, an adolescent boy, or just flat love explosions.

"Rambo: First Blood Part Two," the official title, is volatile and nonverbal, not to mention badly acted and a threat to world peace. It is also action, pure and simple, a testosterone high from its opening scenes.

Stallone, bristling with guns and big knives, stalks on screen like L'il Abner, with long shaggy hair, Dogpatch boots and a bulging upper torso (freshly pumped up for the film). He plays John Rambo, the bulky trip-wire vet from "First Blood," now released from prison and sent to Vietnam on recon for MIAs. "Do not engage the enemy. Just take pictures," warns Richard Crenna, reprising his role as Rambo's mentor, Colonel Trautman. Rambo sneers.

The gonzo guerrilla fighter parachutes into Nam, but loses all his equipment on the way down, except for a serrated knife the size of a machete and a bow with exploding arrows. Betrayed by a cold-blooded politician at home base, he takes up with a Vietnamese agent (Julia Nickson), finally avenging himself against anyone and everyone who stands in his way.

Never one for a lot of dialogue, Stallone lets his guns do the talking. Weaponry outweighs acting considerations, with the various players armed with everything from AK-47 assault rifles to Heckler and Koch MP5K 9mm sub- machine guns. There's shooting aplenty, strangling and stabbing, too.

It would all be just another GI Joe adventure, if you didn't get the feeling that Stallone, who cowrote the comic-book screenplay, was pandering to blind patriotism and blurring the realities of yesterday.

Stallone, a man as partial to Roman numerals as right-wing tastes, continues in this vein later this year in "Rocky IV," when he boxes a Russian. Previews advise, "Get ready for the next World War." Scary stuff, Sly.

RAMBO: FIRST BLOOD PART II (R) -- At area theaters.