Live by Night is a 2016 crime film written, directed, co-produced and starring Ben Affleck as Joe Coughlin, a Boston gangster during the time of Prohibition who also happens to be the estranged son of a Boston police captain and who starts running a bootlegging operation in Florida. The film was adapted from a novel by Dennis Lehane (the author of Mystic River and whose novel Gone Baby Gone was previously adapted into a film by Affleck). The cast includes Elle Fanning, Brendan Gleeson, Sienna Miller, Zoe Saldana, Titus Welliver and Chris Cooper, the latter two who also co-starred in Affleck's 2010 directorial effort The Town.
The film was also co-produced by Leonardo DiCaprio.
The following weapons were used in the film Live by Night (2016):
A bank guard fires a 4-inch .38 police revolver, likely a Colt Official Police during a robbery.
Colt Police Positive
R.D. Pruitt (Matthew Maher) shows up to his meeting with Coughlin with a revolver tucked in his belt. While it's never drawn and not seen in detail, the revolver resembles a Colt Police Positive.
Shotguns
Winchester Model 12
Coughlin's second man during the bank robbery carries a cut-down Winchester Model 12 shotgun which he uses to great effect during the getaway. A gunman is also seen firing an unmodified 1912 during the final shootout.
Double Barrel Shotgun
R.D. Pruitt (Matthew Maher) shows up to his meeting with Coughlin accompanied by two thugs wielding double barreled shotguns.
Submachine Guns
Thompson M1921A
The cops pursuing Coughlin and his gang after the bank robbery fire M1921A Thompson submachine guns, noted by their lack of barrel compensators, from their moving police cars. While the Thompsons are period-correct models, the 30-round stick magazines they're loaded with are anachronistic due to their not being manufactured until 1942. The 20-round magazines would have been appropriate for the time of the film. One of Coughlin's gunmen also uses a M1921A with a 50-round drum in the climactic gun battle. One gunman is seen briefly wielding a Thompson with the buttstock removed.
Thompson M1921AC
The Thompson M1921AC is seen in the hands of multiple gangsters, including Dion Bartolo, throughout the film. They're are seen the most during the climactic gunfight, during which gunmen on both sides wield Thompsons.
Rifles
M1903 Springfield
One of Coughlin's gunmen is seen with a M1903 Springfield during the final shootout. It appears to be a period-correct Springfield (Not a 1940s WWII model), indicated by the humped upper-handguard.
Machine Guns
Browning Automatic Rifle
Joe Coughlin wields and fires a customized Browning Automatic Rifle during a shootout. This particular gun resembles the famous sawed-off BARs used by Bonnie and Clyde, and also the ones used in the film Public Enemies. The major difference is that while the barrel is shortened, the one in the film also has a shortened stock, making it a sort of BAR "whippet gun." While the shortened stock and barrel would certainly make the gun more concealable and lightweight ("lightweight" being a relative term for a 16-pound firearm), controlled fire would probably be near impossible. The gun also has a later model sight as opposed to the original WWI model sight, which is considerably rarer. At least one other gunman is seen holding an identical BAR in the film (likely the same gun used in a different scene).