James Butler "Wild Bill" Hickok (Jeff Bridges) carries, as the real Wild Bill did, two Colt 1851 Navy revolvers, sometimes using a red sash around his waist in lieu of a holster. However, the Colt Navys used in the film are the Richards-Mason cartridge-converted models, which would be anachronistic to the earlier scenes of Wild Bill firing his revolvers in the 1860s (However, the two Navys he fires during the Deadwood shootout, retrieved for him by Jane, aren't cartridge-converted). Several other characters, notably Jack McCall (David Arquette), Phil Coe (Dennis Hayden), and Ed Plummer (John Dennis Johnston) all have cartridge-converted Navy revolvers.
Winchester Model 1866 "Yellow Boy"
An Indian encountered by Wild Bill while buffalo-hunting in the 1860s has a Winchester Model 1866 "Yellow Boy". Will Plummer (Bruce Dern) also has one in a flashback to Wild Bill's duel with Ed Plummer.
Calamity Jane (Ellen Barkin) keeps a nickel Quickdraw Single Action Army as her primary sidearm, best seen when Wild Bill first arrives in Deadwood in August 1876. Will Plummer (Bruce Dern) also uses an SAA, an Artillery Model, during his duel with Wild Bill in Kansas City.
Remington 1866 Derringer
Lurline Newcomb (Christina Applegate) keeps a Remington 1866 Derringer which she gives to Jack McCall (David Arquette) who ties it up his sleeve and uses to assassinate Wild Bill inside Nuttall & Mann's No. 10 (even though the real McCall had used a single-action .45 caliber revolver, although this film makes many historical errors for the sake of its storytelling).
Colt 1860 Army
During the flashback to Wild Bill's shootout with the McCanles Gang in 1860, one of the gang has a Colt 1860 Army.