One of the most frequently used guns in the film is Beretta 92F. It's used by most of major and minor characters. For example Lou (Christopher Lambert) seen using four different 92F's (including one taken from african-american thug named Blondie (Jahi J.J. Zuri) three of which he tosses in the process of the game. He, Bob Jerry Rector and Crow (Thom Mathews) are only characters, that using this guns akimbo (Macedonian) style. Cam (Deborah Van Valkenbourgh) recieves her Beretta 92F gun from Marcus (Michael Halsey), who, most likely takes it from one of the killed criminals.
Barbie (Tina Cote) uses Beretta 92F (taken from Lenny, thug, she killed with baseball bat) to kill another thug.
There's also various thugs (including Ricky (James Wellington) using Beretta 92F (most likely even the same props) during the film.
Desert Eagle Mark VII
Desert Eagle Mark VII it's Marcus (Michael Halsey) own gun. It's the only gun, not taken by Moon guards, possibly because of Marcus's status in syndicate, or because his nonsense phrase about eggs and bacon, he says to the guard is a special password to save own gun, while in the prison.
He uses this gun all the movie, also using other Desert Eagle and an unknown shotgun.
Other Desert Eagle variants
Marcus's gun is not th only Desert Eagle used in the movie. Different variants of it used as frequent as Beretta 92F.Desert Eagle is D (Kimberly Warren) primary weapon. D's Desert Eagle also used by Lou in one scene. Hoss (Yuji Okumoto) gives his own Desert Eagle to the guard, after jokingy aiming it at him, while Crow (Thom Mathews) saying "Bang.". Crow himself uses Desert Eagle (akimbo style with Beretta 92F) in the climatic shootout in the toilet. Moon (Ice-T) carries special case with four chrome Desert Eagles for "Grand Finale". This guns later used by winners - Lou, Cam, Marcus and Moon himself.
Desert Eagle also used by some thugs and one of the Moons guards.
Colt Trooper Mk V
Syndicate boss Vincent Moon (Ice-T) weapon of choice is Colt Trooper MkV revolver. He's shot four people with it through the movie - Comissioner Guilbert (Hoke Howell), biker (Moss Mossberg), long-haired , beardead hippy and an unknown long-haired thug.
Ruger Security Six
Moon's Ruger Service Six anchestor - Ruger Security Six seen in the movie hold by Blondie (Jahi J.J. Zuri) when all the thugs starting to click their empty guns to each other. It's later used by Cam (Deborah Van Valkenbourgh) in the climatic shootout. it's possible that it's the same revolver, cause Blondie's killed by lou, when cam fails to do it.
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Colt Model 1908 Vest Pocket
In the climatic shootout in the toilet, while reloading Hoss and Crow guns, Barbie finds nickel-plated Colt Model 1908 Vest Pocket lying on the floor. She picks it up and uses it later to kill wounded Hoss.
Mossberg 500 cruiser
Bob uses Mossberg 500 Cruiser twice in the movie. He seen with it just before beginning of the game and later uses it, shooting Hoss, crow and barbie while he's wounded. It's possible, that he just hide shotgun somewhere or picked up another.
Also Moon seen on photos with Mossberg 500 Cruiser.
Unknown M1911 pistols
There is M1911 pistol used by one of the thugs in climatic shootout.
Unknown revolvers
D seen using unknown revolver, when all the thugs start to clicking empty guns to each other.
Then it suddenly changed to Desert Eagle, that D used during most of the film.
Unknown revolver (Colt Python ?)
Looks more like a Colt Trooper with a robbed barrel to me. A Python has a full length rib on top and a full length heavy barrel.
Hoss seen using unknown revolver (Colt Python ?) in the climatic shootout in the toilet.
Unknown shotguns
Lou and Marcus using same system unknown shotguns through the film. Also Hoss and Crow using shotgun, fitted with lighthing sight, taken from long-haired thug named Joey. Other shotguns used by some thugs through the film.
Unknown supressed pistol
One and only supressed pistol belong to girl briefly seen in the movie twice in the beginning. It can be another Beretta 92F.
Unknown pistols
There's a few unknown pistols, used by various thugs through the film aside of Beretta 92F
Unknown revolver
Guy, who says, that he will kill all, especially Moon and his family (though then he killed himself by Hoss and Crow) fires and reloads unknown revolver.
Video cover
One one of the films video cover Moon and Lou depicted with pistols, they actually didn't using in the movie.