Based on the barrel look it looks to be a Queen Anne pistol, or if indeed being a pocket pistol, the Liegi derringer
Colt Model 1849 Pocket Model
During the Theatre Scene an Assassin (Bronco Mcloughlin) attempts to kill Bill "The Butcher" Cutting (Daniel Day-Lewis) with a Colt 1849 Pocket Model Revolver
Amsterdam (Leonardo DiCaprio) attempts to assassinate Bill "The Butcher" Cutting (Daniel Day-Lewis) by throwing a knife and then pulling an Elgin Cutlass Pistol, only to be impaled by a knife thrown by Cutting
During the Draft Riots Scene, a mob breaks into the residence of Mr. Schermerhorn (David Hemmings) and he in turn uses two Colt 1851 Navy Revolvers to fend them off.
During the scene where William Tweed (Jim Broadbent) is conversing with Dead Rabbits, Amsterdam (Leonardo DiCaprio) appears to have a Colt Cap & Ball Revolver tucked in his waistband, the same gun is seen, during the debate scene.
There is a good possibility that this is the 1849 Pocket Model, that he took off the assassin who tried to kill Bill earlier.
During the scene where William Tweed (Jim Broadbent) is conversing with Dead Rabbit supporters, Jenny Everdeane (Cameron Diaz) keeps a Sharps Rifle aimed on him
An Irish immigrant is seen being issued a Springfield Model 1842 Musket. This is historically correct, as the Irish Brigade were issued the 1842 Musket until 1864, as it was preferred for its ability to use the "buck and ball" load.
There are numerous firearms in the movie that are hard to identify
File:Unknowngun1.pngAmsterdam (Leonardo DiCaprio) pulls out an unidentifiable second gun during his assassination attempt on Bill Cutting (Daniel Day-Lewis).Error creating thumbnail: File missingA Man to the right has a pistol of unknown make or model drawn.Error creating thumbnail: File missingTwo men to the right have pistols drawn, one looks to be maybe a ducks foot pistol, the other appears to maybe be an over/under pistol.Error creating thumbnail: File missingA musket barrel, possibly a Springfield musket can be seen to the rightFile:Unknowngun2.pngNumerous villagers in the background carry unidentifiable riflesFile:Unknowngun3.pngThe villager in the middle has, what looks to be a pistol of some kindFile:Unknowngun4.pngThere is a gun case in the back left behind the guy with the black hair who is holding a wine cup, full of riflesFile:Unknowngun5.pngRioters raid the gun case in Mr. Schermerhorns' (David Hemmings) house, rifle are hard to identify. One appears to be a Sharps, judging by the trigger guard.File:Unknowngun6.pngTwo of the Tammany Hall representatives stand at the window during the Draft Riots, holding unknown rifles
