The following weapons were used in the film Falling Down:
Colt Mk IV Series 70
A Colt MK IV Series 70 is used in the final scenes in which William 'D-Fens' Foster pursues his family and is confronted by Detective Martin Prendergast (Robert Duvall). The gun was most likely obtained from the "gun bag" of the Latino gang, however it could have also been taken from Nick the Neo-Nazi's surplus store. Notice the two tone Blued finish typical of the Colt MK IV Series 70 pistols.
Smith & Wesson Model 19 Snub Nose
Smith & Wesson Model 15
A Smith & Wesson Model 15 .38 cal revolver with a 4 inch barrel is the service weapon of Detective Martin Prendergrast (Robert Duvall). He hands it over to the police clerk at the beginning of the movie due to his impending retirement.
Smith & Wesson Model 30
What appears to be a Smith & Wesson Model 30 is seen hanging from the door of the crashed car, and is picked up by'D-Fens'. D-Fens then puts the revolver in the bag with the rest of the guns.
Colt Police Positive
A Beretta 92F is seen in the holster of an LAPD officer.
A Intratec TEC-9 that has been converted to full auto is seen several times throughout the film. It is first used by "Gang Member Two" (Eddie Frias), a member of the Latino street gang during the drive-by shooting, then used by William 'D-Fens' Foster (Michael Douglas) in the scene at the Whammyburger restaurant.
A MAC-10 is used by William 'D-Fens' Foster to destroy a phone booth.
"Gang Member One" (Agustin Rodriguez) attempts to shoot William 'D-Fens' Foster with an Uzi, but misses, and it is later picked up and used by William 'D-Fens' Foster to wound him. There are rubber bands around the grip to keep the grip safety depressed so firing could be done quicker and without a full grip on the firearm.
Remington 870 (sawed-off)
A cut-down Remington 870 shotgun with a cut down buttstock is used by William 'D-Fens' Foster to shoot a golf cart and accidentally threaten the caretaker of a rich doctor's house.
An M72 LAW is used by William 'D-Fens' Foster to destroy a large crane. It was obtained from the store of the Neo-Nazi surplus seller. The weapon is inaccurately portrayed as a heat-seeking guided missile, as opposed to an unguided rocket (its real-life role). Strangely, "D-Fens" manages to fire the weapon without turning off the safety or even pressing the trigger.
A Browning M1919A4 machine gun with portions of the side receiver wall cut away is seen mounted from the ceiling in the surplus store.
An oversized replica of an M60 machine gun is also seen in the surplus store.
Bag of Guns
D-Fens picks up the gang's bag full of illegally obtained (some fully automatic) guns after the botched drive-by, and subsequently uses the weapons it contains throughout the film. The entire bag's contents are never fully seen, and only a few of the guns are seen, such as a few submachine guns, a few handguns and a sawn-off shotgun. Interestingly, he never uses the same weapon more than once.