During "Bad Day at Black Rock" (S03E03) the Taurus PT92AFS briefly changes to a Beretta 92FS Inox with the grips painted white. This is likely a replica or rubber gun, as the weapon is used for a stunt.
Desert Eagle Mark VII
Bela Talbot (Lauren Cohan) carries a nickel plated Desert Eagle Mark VII when she confronts Dean in "Bad Day at Black Rock" (S03E03).
Glock 17
A 3rd generation Glock 17 is briefly seen in the mobile home belonging to Kubrick (Michael Massee) in "Bad Day at Black Rock" (S03E03).
A COP 357 Derringer can briefly be seen in the Kubrick's weapon collection in "Bad Day at Black Rock" (S03E03).
Walther PPK/S
A Walther PPK/S can briefly be seen in the Kubrick's weapon collection in "Bad Day at Black Rock" (S03E03). The Walther PPK/S is also the standard pistol used by Bela Talbot (Lauren Cohan).
AMT Automag III
An AMT Automag III can briefly be seen in the Kubrick's weapon collection in "Bad Day at Black Rock" (S03E03).
Ruger P89
A COP 357 Derringer can briefly be seen in the Kubrick's weapon collection in "Bad Day at Black Rock" (S03E03).
Colt Defender
A Colt Defender can briefly be seen in the Kubrick's weapon collection in "Bad Day at Black Rock" (S03E03).
A Wildey Hunter is seen in the trunk of the Impala during the alternate future portrayed in "Mystery Spot" (S03E11). This weapons compartment was originally seen in the back of John Winchester's 1983 GMC Sierra in Season 1.
Vektor CP1
A Vektor CP1 is seen in the trunk of the Impala during the alternate future portrayed in "Mystery Spot" (S03E11). This weapons compartment was originally seen in the back of John Winchester's 1983 GMC Sierra in Season 1.
Colt Mustang Plus II
A Colt Mustang Plus II is seen in the trunk of the Impala during the alternate future portrayed in "Mystery Spot" (S03E11). This weapons compartment was originally seen in the back of John Winchester's 1983 GMC Sierra in Season 1.
Beretta 92FS
Various members of the Sheriff's Department in "Jus In Bello" (S03E12) use Beretta 92FS pistols.
SIG-Sauer P228
FBI Deputy Director Steven Groves (Peter DeLuise) carries a suppressed SIG-Sauer P228 in "Jus In Bello" (S03E12).
"The Colt" (Colt Paterson 1836 cartridge conversion)
"Back in 1835, when Halley's Comet was overhead, same night those men died at the Alamo, they say Samuel Colt made a gun. A special gun. He made it for a hunter. A man like us, only on horseback. Story goes, he made thirteen bullets. This hunter used the gun a half dozen times before he disappeared, the gun along with him... Somehow Daniel got his hands on it. They say... they say this gun can kill anything."
The pistol which is simply referred to as "The Colt" is a modified Colt Paterson 1836, first seen in Season 1. The actual gun appears to be built from a Pietta "Paterson Extra Deluxe" based on the engravings and silver inlay markings. The pistol is further modified with a cartridge conversion, by having a pentagram carved into each grip plate, and the barrel is engraved with "non timebo mala" which translates to "I will fear no evil" (a reference to Psalm 23).
The young Dean Winchester (Ridge Canipe) keeps a Ruger Speed Six under his pillow in "A Very Supernatural Christmas" (S03E08). A Ruger Speed Six is also used by Ben Waters (John Shaw) in "Long-Distance Call" (S03E14).
Side by Side Sawed Off Shotguns are one of the most common weapons on the show, normally being used by the brothers whenever they are hunting a ghost. They are said to be loaded with rock salt shells due to the fact that spirits are repelled by salt.
Ithaca 37 (Sawed Off)
A sawn off Ithaca 37 is used by the brothers on several occasions, most commonly when hunting ghosts loaded with rock salt shells. It is also commonly used as a prop to hold open the lid of the weapons compartment in the trunk of the Impala.
Remington 870
Isaac (Peter Macon) carries a Remington 870 with wood furniture in "The Magnificent Seven" (S03E01).
Franchi PA3
A Franchi PA3 can be seen in Kubrick's mobile home in "Bad Day at Black Rock" (S03E03). Only the grip is visible, but this matches the grip found on Franchi shotguns. Also the very bottom of the forward grip is visible, indicating this is a PA3 as opposed to a longer variant such as the PA8 or SPAS-12.
Winchester Model 1912
A Winchester Model 1912 can be seen in the storage locker belonging to John Winchester in "Bad Day at Black Rock" (S03E03).
Remington Model 870 (Sawed Off)
Dean finds a sawed off Remington Model 870 in the storage locker belonging to their father in "Bad Day at Black Rock" (S03E03). Dean says it was the first sawed off he ever made, and takes it with him when they leave.