In Vietnam, Dugan and Cleon can be seen using their 1911A1 sidearms.
Colt M1911A1 (Nickel)
During the robbery, a nickel plated model M1911A1 is used by both Kirby (Keith David), who fires a whopping 11 rounds without locking, and Skip blows alway the NYPD Officer on beat (Chris Tucker).
During a confrontation with Anthony, Cutty (Clifton Powell) is seen drawing a well polished nickel plated Colt Combat Commander in 9mm (denoted as a 9 by the smaller chamber and bore diameter) from his coat, and aims it at Anthony's head, telling him to "suck it."
Revolvers
Smith & Wesson Model 36
After Kirby (Keith David) goes to collect some debts with Anthony (Larenz Tate) as his unknowing getaway driver, a woman threatens him with a small silver revolver. He easily wrestles it from her, and is attacked by another man from the shop, who accidentally takes Kirby's prosthetic leg off. Kirby falls to the floor and aims at him, claiming the entire time everyone in town knows he has one leg, and he pulled the wrong one. As they get away in Kirby's car, Anthony notices Kirby set down the revolver, which is quite obviously a nickel plated Smith & Wesson Model 36. Another blued Model 36 "Flat Latch" is seen on the table in the planning room, and is used as Anthony's sidearm during the robbery, from which he fires 3 rounds before running out of ammunition on the second police officer he attempts to kill with it.
Smith & Wesson Model 10
The police officer who attempts to intervene in the armored truck robbery uses a Smith & Wesson Model 10. He is drawn by Kirby's 11 rounds fired from his Commander, and returns 9 of his own from his six shot revolver, making their gun battle highly fictitious. Another Smith & Wesson Model 10 is used by Joe (Freddy Rodriguez) in the planning room, and after the robbery as he fires 8 rounds without reloading at a pursuing police car.
Colt Official Police
Most of the police officers guarding the armored car carry a version of the Colt Official Police with a 4 inch barrel and a semi rounded front sight post.
Shotguns
Mossberg 590
During Anthony's tour in Vietnam, he carries an anachronistic Mossberg 590 shotgun, which wasn't introduced until 1987. In order to make the shotgun resemble a more accurate Mossberg 500, the 590's original wood has been replaced with sporting wood taken off of a 500C model.
Remington 870
Anthony's primary weapon during the armored truck robbery is a Remington 870 equipped with a pistol grip, and a short vent rib barrel.
Ithaca 37
As the armored car driver (Richard Riehle) notices the gang moving in on the car, he calls "ambush" and a police officer in the back seat racks an Ithaca 37 and points it through the slit in the van, firing on Joe.
Rifles
M16A1/XM16E1
Many of the men in the Marine Recon unit use the M16A1 rifle. Lieutenant Dugan's is noteworthy in that it is an M16A1, but it has the original M16 three prong flash hider, indicating that it was mocked up to resemble the XM16-E1. Historically this would be unnecessary, since the M16-A1 was already wide spread in the field throughout Vietnam by the 1970s.
Norinco Type 56 (AK47 and SKS)
During the night Recon mission, the Recon unit is fired upon, most of their enemies being armed with Norinco Type 56s, both the AK47 and SKS clones.
Submachine Guns
M3A1 "Grease Gun"
As Anthony is the designated shotgunner, the platoon Staff Sergeant, Cleon (Bokeem Woodbine) is the designated autogunner. He carries an M3A1 "Grease Gun", which in the movie has a very memorable muzzle report and slow fire rate. The sound of fire for this weapon, is obviously taken from a much larger caliber weapon.
PPSh-41 Submachine Gun
When searching for intel, D'Ambrosio (Michael Imperioli) finds a PPSh-41 Submachine Gun and moves it from one of the bodies.
Machine Guns
RPD
When Dugan goes for cover after unloading his 1911A1, we see that a machine gun crew armed with a Soviet RPD Light Machine Gun is firing upon him. It is not the Chinese copy as the front sight has an open hood.