Adapting a good crime writer is never easy but Dennis Lehane's prose is more cinematic than most and he writes lovely, loping dialogue that lifts his characters above the mundane. At least he does in Live by Night, a 500-page epic about a Boston crook named Ben Coughlin who becomes a kingpin in the rum-running trade out of Florida in the 1920s.

Ben Affleck should have been perfect for this. He has adapted Lehane before in Gone Baby Gone and the argot of Boston is second nature; he's even played a Boston gangster before in The Town, directing himself. What could go wrong?

Nobody makes the right artistic decision every time. The things he gets right here should be enough to carry the picture through, yet they do not.

If he had been less ambitious, the cracks would not show as much but he wants this gangster drama to qualify for the first division – which is to say, the Italian league. You know, the one where Coppola, Scorsese, De Palma and Cimino established the benchmarks.

Specifically, I think he wants Live by Night to touch the hem of Sergio Leone's masterpiece from 1984, Once upon a Time in America. He seeks the same sweep of history, the magnificent costumes and opulent locations, the balletic shootouts and intimate betrayals.

And he wants to say some big things about America, because that is the proper subject of the American gangster movie – American business, not simply American crime.

The first problem for a gangster film is the moral one: how to make us side with a bad man. The character has to be so attractive – which is not the same as handsome – that we go along with him.

That's often done by giving us enough of his past that we can see why he is the way he is. Lehane doesn't bother with that in the book.

Joe Coughlin has been a petty crim since 13 and we're never told why. He doesn't get along with his father, a superintendent of the Boston police, but there's no pop psychology.

For the film, Affleck thinks he has to invent some so he puts a lazy couple of sentences on Ben Coughlin's opening narration: he enlisted in 1917, saw too many men die, vowed never to follow the rules again. That's his first mistake.

It might have carried some weight if Affleck's performance had any hint of war-weariness but it does not. His second is to try to make Coughlin a half-bad guy rather than a killer. He doesn't associate with gangsters, he tells a very prominent gangster – like he gets to choose.

By 1925, he's just a minor bank robber with two big problems: three coppers were killed in his last heist and he's sleeping with the girlfriend of Albert White, the second biggest gangster in Boston, played with memorable snarl by Robert Glenister.

The girl, Emma Gould (Sienna Miller), is trouble but he can't get enough of her. Brendan Gleeson, as Thomas Coughlin, the senior cop, has a memorable scene putting her down as a cheap chippy.

In the second half, Ben and his faithful triggerman Dion Bartolo (Chris Messina) move to Ybor, the booming immigrant district of Tampa, Florida, to take over the rum trade. Maso Pescatore (Remo Girone), a Boston godfather, sends them to disrupt the southern businesses of arch enemy Albert White.

Ben falls for Graciela Sanchez (Zoe Saldana), whose family controls the molasses coming from Cuba.

So now we have all the elements for a first-class gangster pic: scores to settle, money to be made, battles to fight, women to love. And there's one more fresh thing: Ben upsets the KKK, in the form of a particularly unattractive redneck killer played by Matthew Maher. That foregrounds the simmering issue beneath all of this story – race.

In costumes, period settings, locations. the film is top class. In action and gunfights, ditto.

The cast performs well. And yet it's an empty shell of a movie.

Affleck seems not to have invested much of his soul here. He leaves most of the acting to a series of increasingly expensive suits; this eventually becomes comical when he struts around in a cream tropical suit that's three sizes too big. A big gun does not a gangster make; a big fedora neither.