A Colt Anaconda is 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.
Colt Python
A snub-nosed Colt Python is used by the Aggressive Panhandler (Michael Paré) to hold up the Postal Dude (Zack Ward) early in the film. Pythons are also used by at least one guy in the trailer park shootout.
Ruger Redhawk
The Postal Dude (Zack Ward) takes a Ruger Redhawk with a 7.5" barrel and black rubber 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 although she is not seen taking it from the Postal Dude's holster.
Ruger Speed Six
A Ruger Speed Six is used by Vince Desi in a cameo, but is quickly taken from him by the Postal Dude. Karen (Holly Eglinton) also uses a Speed Six in Uncle Dave's mansion.
Smith & Wesson Model 10
What appears to be a Smith & Wesson Model 10 is seen in the hands of a member of the local doomsday cult, the Denomination of Organic Monotheism (D.O.O.M.).
A man in the trailer park shootout uses what appears to be a 6" Smith & Wesson Model 586 with Pachmayr grips. Another 586, this time with wooden grips, is used by a different Paradise resident.
A Smith & Wesson Model 66 is seen in the hands of a guy who participated in the trailer park shootout.
Unknown Revolvers
Pistols
Beretta Cougar
Beretta Cougars are the sidearms of both Officer Greg Sharp (Chris Spencer) and Officer John Mann (Ralf Moeller). One is also used by Uwe Boll in a cameo during the Little Germany 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). During the trailer park shootout, there is a continuity error where Officer Greg (Chris Spencer) picks up a 92FS before exiting a trailer, but when he steps outside he is holding a Beretta Cougar instead. Shortly afterwards when he steps back inside, the Cougar turns back into a 92FS. Starr (Lorielle New) also carries one in Richard's underground bunker.
Beretta 92SB
When the Postal Dude attaches a cat to his 92FS for use as a makeshift silencer, the weapon turns into a Beretta 92SB.
CZ 75
The Postal Dude briefly utilizes a high polish stainless "Pre-B" CZ 75 during his escape from Dave's mansion. Later, a man uses a CZ 75 with wooden grips during the trailer park shootout; in some scenes, his pistol is a Pre-B while in others it is a CZ 75B. Strangely, he is seen emptying his pistol (as evident from the slide locking back), but continues to point and pretend to shoot it, with digital muzzle bursts added in post-production.
Glock 17
A disgruntled customer (Michael Eklund) uses a Glock 17 taken from a security guard in the social security office. Other security guards are also seen using the pistol.
IMI 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). Chromed or nickeled versions are used by Jenny (Michaela Mann) and Cindy (Lucie Guest) in Dave's mansion during the shootout with the terrorists. The Dude also appears to use a regular one during the same shootout, although he quickly ditches it in favor of his Redhawk.
M1911A1
An M1911A1 is used by a woman in the trailer park shootout.
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.
Smith & Wesson 5904
Multiple Paradise residents are seen using Smith & Wesson 5904s, most notably by a woman in the trailer park shootout.
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, and a final one is seen in the hands of one Richard's thugs.
Submachine Guns
Heckler & Koch MP5K
A terrorist uses a Heckler & Koch MP5K in the trailer park. Two MP5Ks are also wielded akimbo style by one of the trailer park residents.
Heckler & Koch MP7
The Taliban/al-Qaeda terrorists use Heckler & Koch MP7s during the Little Germany and trailer park shootouts. Some of them are fitted with ELCAN scopes and side rails.
A TEC-9 is used by Faith (Jackie Tohn) in the trailer park shootout.
Rifles
Adler-Jäger AP-80
An AK rifle appears leaned against a wall on a crate in Richard's (Chris Coppola) bunker. Although poorly seen, it appears to have a thin magazine, indicating that it is likely an Adler-Jäger AP-80 .22 LR replica.
AKS-47
Mohammed (Michael Benyaer) carries an AKS-47 while inside Uncle Dave's mansion instead of his usual Zastava M70AB2. What appears to be the same weapon is also seen in the hands of another terrorist in the mansion and in the set of Osama bin Laden's (Larry Thomas) recordings.
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.
Heckler & Koch G36K
Heckler & Koch G36K rifles are seen in the hands of Taliban/al-Qaeda terrorists. Some of them have the ZF 3x4° dual optical sight while others have the singular export sight. Most have a vertical grip attached.
An 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 appears to have a green stock.
The Zastava M70AB2 is the primary weapon of Mohammed (Michael Benyaer). Osama bin Laden's AKS-74U also turns into an M70AB2 when he arrives at Little Germany.
Unknown Bolt-Action Rifle
A man in the trailer park shootout is seen with an unidentified bolt-action rifle on his lap. He never uses it.
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.
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.
Winchester Model 1897
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).
Unknown Shotgun
An unknown pump-action shotgun is used in the trailer park shootout.
Machine Guns
Browning M2HB
A Browning M2HB is used by Richard (Chris Coppola) during the trailer park shootout, mounted on a 1987 Ford Mustang LX convertible, giving the Toyota Hilux some much needed competition.
Daewoo K3
A Daewoo K3 is seen in Richard's doomsday bunker, and is later 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 (2004), Underworld: Evolution, Battlestar Galactica etc).
M60
An M60 is in Richard's secret doomsday bunker. Another M60 is used by one of the Paradise residents against the Postal Dude and Faith during the trailer park shootout.
PKM
PKM machine guns are used by Paradise residents against the Postal Dude and Faith during the trailer park shootout.
An M72 LAW is seen in Richard's bunker buried beneath some rifles.
Pancerovka P-27
What appears to be a Pancerovka P-27 is seen in Richard's bunker.
RPG-7
An 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.