Sylvester Stallone had considerable success going to the nostalgia well last year with “Rocky Balboa,” the sixth installment of the series that began in 1976, and he’s trying the same trick with “Rambo,” the fourth in the series that started in 1982 and had previously ended with “Rambo III” in 1988. It’s possible that boomers who look back on the first three movies with affection will come out for this resurrection of the character, but if they do they’re likely to be astonished as how gory and graphic the new version is. The original Rambo movie was actually titled “First Blood” (after the David Morrell novel on which it was based). This one should be called “Entirely Too Much Blood.”

The plot devised by Stallone closely follows the template of parts 2 and 3, involving the laconic hunk in a rescue operation—this time of a group of missionaries and doctors whom he’d reluctantly ferried in a decrepit boat from his Thai home into Myanmar (insistently called Burma here) so that they could minister to Karen rebel communities, but who’ve been captured by brutal, bloodthirsty government troops. Rambo, whose sense of duty has been reawakened by the female member of the group—Sarah, played by Julie Benz—leads a group of mercenaries hired by their church (!) to save the captives and bring them home. In doing so he and his comrades (though mostly he) wipe out the entire complement of soldiers from the camp in which they’re being held—including of course the vicious commandant (who’s also, we’re shown, a pervert who does it with young men!)—first by invading the compound and then in a tumultuous fire-fight at the river’s shore.

In terms of the look and feel of “Rambo,” what it mostly calls to mind are the chintzy Cannon action flicks of the eighties that usually involved (as “Rambo II” did) missions to free POWs from prisons in Southeast Asia. It has the same grubby look (the cinematography is by Glen McPherson) they did. But they were nowhere near as violent as this. There are probably more exploding bodies, guttings, dismemberments and decapitations in this movie than in any other ninety minutes committed to celluloid. The last thirty minutes or so are pretty much wall-to-wall mayhem, and mayhem of the most gruesome sort. It’s staged in ways that blur the carnage, but the result is still pretty stomach-churning. Yet, as Brian Tyler’s trumpet-laden music insistently suggests, we’re supposed to cheer over it, because the villains are so uncompromisingly horrid, not only mowing down women and children without the slightest scruple but using prisoners in their demented games involving chases through swamps littered with land mines. We’re also supposed to feel a sense of relief when the piously priggish and pacifistic missionary Michael (Paul Schulze), who’s been disgusted by Rambo’s cynical attitude and horrified when he wipes out a bunch of pirates who threaten to have their way with Sarah, finally feel righteous indignation during the final combat and batters one of the brutish soldiers to death with a rock. He finally saw the light, you see.

The transformation of that fellow is pretty much emblematic of the depth of characterization that Stallone’s written into the script. All the figures are one-note affairs; some are just given more screen time than others. So Benz plays Julie without shading as a principled damsel-in-distress, and Schulze Michael as the unrealistic do-gooder who eventually learns you can’t keep turning the other cheek. Each of the mercenaries has his particular shtick, too; so Matthew Marsden is School Boy, the gangly boy-next-door sharpshooter with a decent vocabulary and some honest principle, while Graham McTavish is the foul-mouthed, arrogant Brit who drips with contempt for “boatman” Rambo until the latter shows up unexpectedly at the site of a massacre to dispatch a whole squad of nasty soldiers with his trusty bow-and-arrow. None of the supporting actors distinguish themselves—not even Ken Howard, who pops up briefly as the Colorado pastor from whose church the waylaid missionaries came, and who looks a lot less happy with his assignment than he did as the supercilious corporate lawyer in “Michael Clayton.” But then Stallone doesn’t ask for any layers from his co-stars, either in his writing or in his directing; this is very straightforward, simple-minded action stuff, unencumbered by any thought or doubt—black-and-white at its most extreme (though there’s plenty of red).

As for Stallone the actor, at over sixty he certainly looks pumped up. Excessively so, in fact—his torso, with its bulging muscles, has an unnaturally bulbous appearance (the result, no doubt, solely of long exercise). But in terms of performance, there’s not much to be said. He grunts out his few lines, many of them aimed at provoking a chuckle, in his typical growly style, and shoots out knowing, dismissive stares at those around him with the superior air of a man who can rip out your throat without breaking a sweat (indeed, he does that to a Burmese officer at one point). But frankly the Ultimate Soldier routine gets pretty tiresome after awhile, especially since it’s supposed to be tinged with an air of resignation over the wickedness of the world and, at the end, one of redemption as well (the final pre-credit “coming home” sequence even wants to engender a lump in your throat, but fails).

You have to credit Sylvester Stallone with resuscitating what appeared to be a permanently moribund career by taking his “greatest hits” out of mothballs. But now that Rocky and Rambo are out of the way, could we please have the sequels we really need from him—an “Oscar II” or “Rhinestoner,” or “Stop! or My Mom Will Shoot Again” or—my special favorite—“Even Further Over the Top”? We haven’t had a really good arm wrestling movie in decades. And if “Rambo” is any indication, this time around Lincoln Hawk could actually rip his opponents’ arms out of their sockets and wave them around while blood spurted from the stumps. While we cheer, of course.