The Fourth War is a 1990 drama directed by John Frankenheimer and starring Roy Scheider as Jack Knowles, a US Army Colonel and decorated Vietnam veteran who comes to be at odds with a Soviet colonel (Jürgen Prochnow) at the West German-Czechoslovakia border during the height of the Cold War in the late 1980s.
The following weapons were used in the film The Fourth War:
An early M16/SP1 rifle fitted with A2-style round handguards is notably used by COL Knowles during his secret missions. This particular rifle is also fitted with an underbarrel laser sight. This particular laser-sighted M16 is also used briefly at the end of the film by Lt. Colonel Clark (Tim Reid) after he takes it from one of his men. At the time of filming, the US Army had recently adopted the M16A2.
M16A1 (w/ A2 style handguard)
The majority of the US soldiers in the film carry what appear to be M16A2-style rifles, but close inspection reveals that they are in fact carrying M16A1s with A2 style handguards.
Norinco Type 56-1
What appears to be the Norinco Type 56-1 rifle carried by Soviet soldiers in the film. These rifles have the distinctive full-circle ("hooded") front sights of the Norinco, but have slant muzzle brakes of Soviet-made AK rifles. Most are fitted with bakelite magazines (rather than metal), and at least one seen near the end of the film is fitted with an AK-74-style muzzle brake in an attempt to imitate the Soviet armed forces' service rifle at the time. Colonel Valachev (Jürgen Prochnow) uses one of these rifles that's been fitted with what appears to be a mock-up of a GP-25 Grenade launcher.
Machine Guns
Browning M2HB Heavy Machine Gun
Browning M2 HB machine guns are seen mounted on US Army APCs in the film.
Grenades
M26 Hand Grenade
COL Knowles holds up an M26 hand grenade when confronting some Soviet soldiers.
What appears to be a GP-25 Grenade launcher is mounted underneath the Norinco Type 56-1 rifle used by Colonel Valachev (Jürgen Prochnow). This launcher is clearly a fabricated mockup which likely uses shotgun shells or another form of blank, since the GP-25 was not available to film armorers in the West at the time that this movie was filmed.
RPG-7
The RPG-7 mounted with a PGO-7 scope, is used by Soviet soldier during the final confrontation.
FIM-92A Stinger
During a confrontation with Soviet forces at the German-Czech border early in the film, COL Knowles orders one of his soldiers to point an FIM-92A Stinger at the "Soviet" helicopter (actually an American Sikorsky S-58 painted in Soviet Army markings) which buzzes the armored column under his command. The Fourth War is one of the earliest movies to feature an actual FIM-92A Stinger instead of the earlier FIM-43 Redeye (Fire Birds, which also featured the Stinger, was released nearly two months after this movie).
Helicopters and armor
During the final confrontation, US and Soviet forces respond with many armored vehicles and helicopters. Some of the "Soviet" armored vehicles in this scene appear to have been originally built for Red Dawn.