The Postal Dude (Zack Ward) takes a Ruger Redhawk with black plastic grips from Richard's (Chris Coppola) bunker and uses it for the rest of the film. Faith (Jackie Tohn) also holds it during the Trailer Park Shootout as the Dude engages in hand-to-hand combat.
Smith & Wesson Model 66
A Smith & Wesson Model 66 is seen in the hands of a guy who participated in the trailer park shootout.
What appears to be a Colt Police Positive is seen in the hands of a member of the local doomsday cult, the Denomination of Organic Monotheism (D.O.O.M.).
Colt Python
A Colt Python is used by the Aggressive Panhandler (Michael Paré) to hold up the Postal Dude (Zack Ward) early in the film. Also a 6" version is used by at least two guys in the trailer park shootout.
Colt Anaconda
A Colt Anaconda is also used by Richard (Chris Coppola) throughout the film, most notably using it in his underground bunker and during the film's climax. In the extended German release, a disgruntled Paradise resident fires an Anaconda from a bicycle before he is knocked off of the bike.
Beretta Cougar
Beretta Cougars are the sidearms of both Officer Greg (Chris Spencer) and Officer John (Ralf Moeller). One is also used by Uwe Boll in a cameo during the Little-Germany shootout.
Beretta 92FS Inox
A Beretta 92FS Inox is used by the Postal Dude (Zack Ward) in Uncle Dave's mansion. He tosses it following a shootout.
Beretta 92FS
The Beretta 92FS is seen in the hands of of various characters, especially in the hands of Paradise police officers and the Postal Dude (Zack Ward). Near the end of the film, there is a continuity error where Officer Greg (Chris Spencer) steps out of a trailer with his Beretta Cougar before stepping back inside to take cover from gunfire. The next shot in the trailer shows him holding a 92FS instead. One of Uncle Dave's chicks also carries one in Richard's underground bunker.
CZ 75B
A CZ 75B is used by a man in the trailer park shootout. He appears to run empty yet he keeps continues to mime fire the gun during the shootout with the slide locked back.
Glock 17
Glock 17 pistols are seen in the hands of the security guards during the social security office shootings. Also used by a disgruntled customer, who takes one from a security guard.
Smith & Wesson 5906
A Smith & Wesson 5906 is used by the Postal Dude (Zack Ward) in the both the alley shootout and the trailer park shootout. One is also used by a customer at the social security office. A final one is seen in the hands of one Richard's thugs.
Para Ordnance P-14
A Para-Ordnance P-14 is seen in the hands of Faith (Jackie Tohn) during the Little Germany shootout and the trailer park shootout.
Jericho 941 R
Jericho 941 R pistols are seen in the hands of a number of Paradise residents as they hunt for the Postal Dude (Zack Ward). A chromed version is used by one of the chicks in Dave's mansion during the shootout with the terrorists.
The Taliban/al-Qaeda terrorists also use MP7s during the trailer park shootout. At least three are seen throughout, the two down below and another one is scene without any sort of sight attachment and the fore-grip folded. (Could someone possibly ID that sight?)
Heckler & Koch MP5K
Two Heckler & Koch MP5Ks were wielded akimbo style by one of the trailer park residents. It didn't work out well for her.
TEC-9
A TEC-9 is used by Faith (Jackie Tohn) in the trailer park shootout.
At least one Mauser Kar98k rifle can be seen in Richard's (Chris Coppola) secret doomsday bunker.
Heckler & Koch G36K
Heckler & Koch G36K rifles are seen in the hands of Taliban/al-Qaeda terrorists. Some of them have their stocks removed. Most have a vertical grip attached.
AKS-74U
A AKS-74U is used by Osama Bin Laden (Larry Thomas) as his main weapon throughout the film, with the exception of his attack on Little Germany.
Zastava M70BA2
Zastava M70AB2 rifles are seen in the hands of Taliban/al-Qaeda terrorists.
AKMS
An AKMS type weapon is seen in the hands of a Taliban/al-Qaeda terrorist in Dave's mansion.
A M14 rifle is used by one of the Paradise residents against the Postal Dude (Zack Ward) and Faith (Jackie Tohn) during the trailer park shootout. It's green in color.
Shotguns
Remington 870
When Officer Greg (Chris Spencer) investigates an elderly Chinese woman that wasn't moving her car when the traffic lights changed color, he carries with him a Remington 870 shotgun. When she defends her case in Chinese, Greg shoots her. He then claims that she called him "Nigger."
Ithaca 37
Ithaca 37 shotguns are seen in the hands of various Paradise residents and at least one terrorist.
Mossberg 500A Field Gun
A Mossberg 500A field shotgun is seen in the hands of a Paradise resident during the trailer park shootout.
Winchester 1897 shotgun
A Winchester Model 1897 is used by The Postal Dude's irritating neighbor during the trailer park shootout. He only fires it once before the gun jams, much to his dismay (and demise).
Machine Guns
Daewoo K3
A Daewoo K3 is used by the Postal Dude (Zack Ward) for two shootouts. He manages to get out of both of the sizely shootouts unscathed and with one hundred percent casualties on his aggressors. Since Postal was filmed in Vancouver, British Columbia, Canada; the Daewoo K3 machine gun seen in this film has been used in many TV shows and movies that were filmed in Vancouver e.g. Stargate: SG1,Stargate: Atlantis, Walking Tall, Underworld: Evolution, Battlestar Galactica etc. In the trailer park scene it clearly fires blanks.
M60 machine gun
A M60 was in Richard's (Chris Coppola) secret doomsday bunker. Another M60 was used by one of the Paradise residents against the Postal Dude (Zack Ward) and Faith (Jackie Tohn) during the trailer park shootout.
PKM machine gun
A PKM machine gun is used by one of the Paradise residents against the Postal Dude (Zack Ward) and Faith (Jackie Tohn) during the trailer park shootout.
Browning M2
A Browning M2 is used by Richard (Chris Coppola) during the trailer park shootout. The M2 machine gun was mounted on a convertible car.
Other Weapons
RPG-7
A RPG-7 is in the hands of a Taliban/al-Qaeda terrorist named Abdul, a mentally handicapped terrorist. He drops it several times, the final time causing it to go off.