The third season of Longmire wrapped up many ongoing storylines, finally unveiling the fate of David Ridges, Branch's shooting, Vic's past in Philadelphia, and most importantly, what happened to Walt's wife in Denver. Although it had the best ratings of any scripted show on A&E, second overall only to reality show Duck Dynasty, A&E dropped the show shortly after the season ended. The network pointed out that while the show was pulling in better ratings than Mad Men or Justified, those rating were coming from a much older demographic, and thus was not as profitable. A&E also couldn't share in any of the profits since it didn't actually own any part of the show. Fortunately, streaming provider Netflix, who owned the streaming rights of the show and was subscriber based, agreed to continue the show, giving the show a fourth and eventually fifth season.
The following weapons were used in Season 3 of the television series Longmire:
Sheriff Walt Longmire (Robert Taylor) carries a Colt Government Model with custom stag grips for his duty sidearm. Unlike most men who choose to carry the M1911, Walt chooses to carry in Condition 2 (mag inserted, round chambered, hammer uncocked) which most M1911 users do not recommend for safety reasons.
Deputy Ferguson, AKA "The Ferg" (Adam Bartley) appears to carry a Smith & Wesson Model 29 as his sidearm. The Ferg is never seen drawing his sidearm during the season.
Smith & Wesson Model 19
Det. Ed Gorski (Lee Tergesen) sticks what appears to be a Smith & Wesson Model 19 in Vic's face in a flashback in "In the Pines" (S03E04). It turns out to be a water pistol filled with Jägermeister. Lucian Connally (Peter Weller) considers a Model 19 in his weapons stash, but opts for a Single Action Army instead in "Wanted Man" (S03E05).
Beretta 92FS
Beretta 92FS pistols are seen throughout the season.
SIG-Sauer P226
A tribal office (uncredited) draws what appears to be a SIG-Sauer P226 in "Wanted Man" (S03E05).
Chance Gilbert (Peter Stormare) uses an unidentified bolt-action rifle in "Wanted Man" (S03E05). The rifle shows up again in the hands of a henchman in "Population 25" (S03E07).
Unknown bolt-action rifle 2
Branch carries an different unidentified bolt-action rifle in "Reports of My Death" (S03E06).
M4A1 Carbine
Some of Chance Gilbert's henchmen are armed with varieties of M4A1 Carbines in "Population 25" (S03E07).
Tokyo Marui M4 S-System
Phil (Ali Agirnas) is armed with what appears to be a Tokyo Marui M4 S-System airsoft rifle standing in for a real rifle in "Population 25" (S03E07).
MGC Replica M16
Trevor (Nando Betancur) is armed with an MGC Replica M16 in "Population 25" (S03E07).
Savage 116
One of Chance's henchmen is armed with a [Savage 116]] in "Population 25" (S03E07).
David Ridges uses a Winchester Model 1866 "Yellow Boy" in "Counting Coup" (S03E09). Since he is riding with it and using it as a club, it is most likely a rubber stunt prop.
Shotguns
Over/Under Doubled Barreled Shotgun
Barlow Connally (Gerald McRaney) is seen cleaning and assembling an O/U shotgun in "The White Warrior" (S03E01). Branch later this particular shotgun in "Counting Coup" (S03E09).
Goof
Branch and his father Barlow are seen trap shooting with O/U shotguns. Despite firing singles (loading one shell for just one bird), the two of them are loading and ejecting two shells through the scene. Although it's plausible that they could've been using two shell on one bird since they're just practicing, only one shot is heard.
Non gun Remington 870
Sofia (Charlotte Alexis White) threatens Walt with a Non gun Remington 870 in "Of Children and Travelers" (S03E02). Alan Little (Chris Freihofer) grabs it briefly after she drops it.
Coach Gun
Henry Standing Bear (Lou Diamond Phillips) uses a Coach Gun supplied by Walt in "Wanted Man" (S03E05). One of Chance Gilbert's henchmen is seen with one in "Population 25" (S03E07)
Mossberg 500
One of Chance's henchmen is armed with what appears to be a Mossberg 500.