Season 2 of Fargo is set in the year 1979, twenty-seven years prior to the events of Season 1, as State Trooper Lou Severson (the character portrayed by Keith Carradine in Season 1 and portrayed by Patrick Wilson here) finds himself investigating a triple homicide that also is connected to a cover up of a hit-and-run murder.
The following weapons were used in Season 2 of Fargo:
What appears to be a nickel Colt Detective Special is seen used by Rye Gerhardt (Kieran Culkin) in Season 2's premiere "Waiting for Dutch" (S2E01). His Colt is a rarer 3" barrel model.
Minnesota State Trooper Lou Solverson (Patrick Wilson) carries a Colt Python as his duty sidearm, the Python appears to be a favorite of Minnesota law enforcement, as it is carried by a few characters in Season 1.
Smith & Wesson Model 10
Hanzee Dent (Zahn McClarnon) pulls a Smith & Wesson Model 10 out of his bag in "The Gift of the Magi" (S2E05). Dent uses the Model 10 during "Loplop" (S2E08).
Smith & Wesson M&P revolver
Rock County, MN Sheriff Hank Larsson (Ted Danson) carries a pre-Smith & Wesson Model 10 Military & Police with a 6" barrel as his duty sidearm.
Pistols
CZ75
The Gerhardt fixer, Virgil (Greg Bryk) carries a CZ 75 as his sidearm in "Fear and Trembling" (S2E04).
Colt 1911A1
In 1951, a younger Otto Gerhardt (Michael Hogan), uses a Colt M1911A1 to dispatch some rival gangsters in "Fear and Trembling" (S2E04). Mike Milligan (Bokeem Woodbine) practices loading a M1911A1 during "The Castle" (S2E09).
Heckler & Koch P9S
A Heckler & Koch P9S is carried by Dodd Gerhardt (Jeffrey Donovan) in a shoulder holster. He is seen handing it to Charlie Gerhardt (Allan Dobrescu) in "Fear and Trembling" (S2E04), so the younger Gerhardt can take some shots.
Luger P08
Karl Weathers (Nick Offerman) carries what appears to be a Luger P08 in a cross draw holster to intimidate Hanzee Dent in "Fear and Trembling" (S2E04).
Remington 1866 Derringer
Mike Milligan (Bokeem Woodbine) fires the Remington 1866 Derringer in "Fear and Trembling" (S2E04). Milligan makes use of the Derringer once again in "Did you do this? No, you did it!" (S2E07).
SIG-Sauer P225
Charlie Gerhardt (Allan Dobrescu) uses a suppressed SIG-Sauer P225 in a assassination attempt in "The Gift of the Magi" (S2E05).
Walther P38
Bear Gerhardt (Angus Sampson) uses a Walther P38 to execute a traitor in "Did you do this? No, you did it!" (S2E07).
Shotguns
Ithaca 37
Wayne and Gale Kitchen (Brad Mann and Todd Mann) both make use of sawn-off Ithaca 37's, most notably in "The Myth of Sisyphus" (S2E03) and to great effect in "The Gift of The Magi" (S2E05).
Remington 870
Remington 870 shotguns are used by Gerhardt family henchmen and Kansas City mobsters. Hanzee Dent (Zahn McClarnon) and Bear Gerhardt (Angus Sampson) both use Remington 870s in "Rhinoceros" (S2E06). Gerhardt henchmen are also largely armed with Remington 870s during "The Castle" (S2E09).
Kansas City mobsters use Winchester Model 70 rifles in "The Gift of The Magi" (S2E05).
Heckler & Koch HK91
A Heckler & Koch HK91 is used by a Gerhardt mobster in "The Gift of The Magi" (S2E05). Mike Milligan (Bokeem Woodbine) holds an HK91 while gearing up in "Rhinoceros" (S2E06). The HK91 is also seen in Milligan's hotel room in "Did you do this? No, you did it!" (S2E07).
M14 Rifle
A Gerhardt mobster uses an M14 Rifle in "The Gift of The Magi" (S2E05).
L1A1 SLR
A L1A1 SLR appears in the hands of a Gerhardt mobster during the standoff at the Sheriff's office in "Rhinoceros" (S2E06). The SLR is also seen in Milligan's hotel room in "Did you do this? No, you did it!" (S2E07).
M16 SP1
Hanzee Dent (Zahn McClarnon) wields an M16 (SP1) rifle while searching for Ed Blumquist in "Rhinoceros" (S2E06). He also uses the rifle in "Loplop" (S2E08) and "The Castle" (S2E09).
Submachine Guns
IMI Uzi
Gerhardt henchmen use Uzi submachine guns in "The Gift of the Magi" (S2E05) and "Rhinoceros" (S2E06). Kansas City mobsters also use Uzis in various scenes.