The two thugs holding up Halim's convenience store during the opening shootout each have a sawed-off Remington 870.
Beretta 92FS
LAPD Sgt. Jack Colt (Emilio Estevez) carries a Beretta 92FS, drawing it in almost every scene of the film. Anytime he is shown drawing the weapon, the sound of a slide being pulled is played to mock other action films. Colt's character appropriately carries the Beretta 92FS as he is almost a direct parody of Mel Gibson's Beretta-carrying character of Martin Riggs in Lethal Weapon and its sequels.
The clerks' translator at Halim's convenience store fires a burst from a flamethrower at Colt and the robbers. It seems to be an M2 that the actor is holding it sideways.
M72 LAW
One of the robbers during the convenience store shootout fires a M72 LAW.
FN FAL 50.61
Colt (Emilio Estevez) fires several rounds from an FN FAL at the robbers, which knocks them flying through the window of the store.
Ruger Mk I
General Mortars' chief henchman Mr. Jigsaw (Tim Curry) uses a suppressed Ruger Mk I to assassinate LAPD Sgt. Billie York (Whoopi Goldberg) in her home. It is identified as a Mk I by the simple rear sights.
Several of the LAPD SWAT officers at the scene of the domestic dispute have Heckler & Koch MP5A3 submachine guns pointed at the apartment.
Uzi
The hoodlums having the "domestic dispute" fire an Uzi at the police below when Luger tells them to "drop their hands and come out with their weapons up". Jigsaw (Tim Curry) is seen later firing an Uzi at Colt and Luger inside the cocaine cookie factory. In a deleted scene, Colt shouts (after he is wounded by Jigsaw) that "It takes more than twelve rounds from an Uzi to kill Ted Zickleman" before realizing someone has taken over his body.
Smith & Wesson Model 15
After an LAPD officer (Corey Feldman) fires his Smith & Wesson Model 15 at the "domestic dispute", Sgt. Wes Luger (Samuel L. Jackson) takes it from him, saying he'll hand it back when he listens to orders. Several other officers carry them, including Larry Wilcox as he reprises his role as Officer Jon Baker from CHiPs.
Glock 19
The FBI agent on the third floor (Paul Gleason) holds a Glock 19 while telling Colt and Luger to leave.
Smith & Wesson 639
One of the FBI agents walking a suspect out of the third floor has a Smith & Wesson 639 with wood grips.
A helicopter gunner, mocking the scene from Lethal Weapon 2, fires a Heckler & Koch HK21 at a trailer. After the trailer blows up, Bruce Willis walks out in a dirty undershirt (similar to his character in the Die Hard series) and complains.
M67 hand grenade
Colt (Emilio Estevez) attaches an M67 hand grenade to his tactical clothing when preparing to take on the cocaine cookie factory.
MGC CAR-15
Spoofing Sylvester Stallone in the Rambo series, Colt (Emilio Estevez) prepares to attack the cocaine cookie factory with several weapons, including a Japanese replica MGC CAR-15 with a 30-round magazine, but falls over due to the weight. It is identified as an MGC CAR-15 due to the metal buttstock, distinctive handguard ring, blued magazine and the fact that the buttstock is fixed in the halfway extended position.
Walther MPL
One of the guards at General Mortars' cocaine cookie factory has a Walther MPL.