C-

Some heist movies are like white-knuckle plane rides. “Armored” feels more like one that starts with a three-hour delay at the gate and is so smooth after departure that you can’t help but snooze. It wants to be “Reservoir Dogs” revisited but winds up like a flaccid television movie instead.

That’s despite the fact that the tale of a bunch of armored-car guards who plan to swipe a big cargo—in excess of forty million bucks—and claim they were robbed, only to have the plan go wrong, boasts a surprisingly strong cast. Among the crew are Matt Dillon as Mike, the world-weary ringleader; Jean Reno as Quinn, the burly long-timer; Laurence Fishburne as Baines, the hot-tempered bully; and Skeet Ulrich as Dobbs, the nervous Nelly (perhaps his name is intended as an homage to Humphrey Bogart’s “Treasure of the Sierra Madre” antihero). Fred Ward is also on hand as their crusty boss. And there are a couple of less-known additions: Amaury Nolasco as Dobbs’s nastier partner, and Columbus Short as newcomer Ty.

It’s Ty who turns on the rest of the crew after they’ve stolen the loot and taken it to an abandoned factory, but messed up the original plan by killing a homeless guy hiding there. He’s always been a reluctant participant, agreeing to the plan only because the bank’s threatening to repossess the family home and the state to revoke his guardianship of his younger brother Jimmy (Andre Jamal Kinney), and killing wasn’t part of the deal. He locks himself inside one of the armored cars along with its cargo, forcing the others to try to bust in. Matters get even more complicated when a cop (Milo Ventimiglia from “Heroes”) shows up and winds up wounded inside with him, and when the guys kidnap Jimmy to try to force Ty to give up.

All of which means two things. One is that for a good chunk of the picture there’s not much to engage your interest except watching the thieves banging incessantly on the hinges of the armored car’s doors to open them and get to Ty. Quite simply, it’s not just noisy but boring; there are entirely too many dust-ups among the robbers and close-ups of sweaty faces. Then there’s the fact that you have to accept the absurd notion that Ty can slip in and out of the car to fetch the cop, set off explosions, make calls on a walkie-talkie, and so on. It may be necessary to drag out the plot to feature length, but it doesn’t just strain credibility—it stomps it to smithereens.

Under the circumstances the cast do what they can, but they’re all playing sketches rather than characters; each is given one defining quality which they just repeat endlessly. (Letting them establish who they are is certainly the rationale behind the flabby twenty-minute opening, which largely consists of their dumb banter and jokey camaraderie and couldn’t be duller.) Short probably comes off best, simply because he’s the purported hero; it’s conveniently forgotten at the end that he was part of the plot, and might even receive a reward for foiling it, and so save his house and what’s left of his family. But then he deserves it—we’re told that he served in Iraq, and nothing’s too good for our conflicted veterans.

Similarly, Nimrod Antal does what he can to keep up the tension, but James Simpson’s script doesn’t give him much to deal with, and the threadbare production, mediocre cinematography by Andrzej Sekula and lax editing of Armen Minasian don’t help. The pulsating, vaguely hip-hop score by John Murphy proves more irritant than pulse-pounder.

So what you can say about “Armored” is that the heist goes awry, but not as badly as the movie itself.