In the nowhere town of Wibaux, Mont., four young men have got 48 hours to retrieve a bag stuffed with $500,000 in Mob cash. Matty (Barry Pepper), the hero of Knockaround Guys, has a hawk nose, an Elvis pompadour, and a look that says ”I dare ya,” but for all of his junior-thug swagger, he isn’t a gangster. He’s the son of a gangster, treated by his wiseguy father (Dennis Hopper) as an errand boy; this is his chance to prove his manhood. Once the money passes from a pair of skate-punk stoners into the hands of a corrupt sheriff (Tom Noonan), how are Matty and his pals going to get it back?
They’re going to start acting like a posse of generic, heat-packin’ tough guys, that’s how. Written and directed by Brian Koppelman and David Levien, ”Knockaround Guys” seems to think that it’s a character study, or maybe an all-in-the-Family portrait on par with ”The Sopranos,” but it has no twistiness or intrigue, and none of the juicy anthro-underworld detail that Koppelman and Levien brought to their screenplay for the tricky, enjoyable ”Rounders.” Vin Diesel, cast as perhaps the strongest-looking man ever to sport a Star of David tattoo, enacts his mano-a-mano showdowns with less of the taunting, mushmouthed fake bluster he displayed in ”XXX,” but Barry Pepper ends up turning coolness into something far too mopey to identify with.