A pivotal weapon in the film, the Smith & Wesson Model 15 used at different points in the film by Wing (Waise Lee), Fai (Jackie Cheung) and Ah Bee (Tony Leung). Most notably, the weapon is used when the three protagonists are held at a Việt Cộng camp, where they are coerced into executing fellow prisoners.
Unknown revolver
Y.S Leong (Lam Chung), a Saigon crime boss, uses an unknown revolver to hold Yan Sau Ching (Yolinda Yam) hostage after Wing, Fai and Bee attack his club.
Pistols
M1911A1
M1911A1 pistols are among the most common weapons in the film, and are used by the protagonists, Vietnamese gangsters and ARVN soldiers.
Auto Ordnance M1911A1
The Auto Ordnance M1911A1 is also occasionally seen in the film, most noticeably during the final scene.
Browning Hi-Power
Some of Mr. Leong's thugs are armed with Browning Hi-Power pistols. Ah Bee also uses a Hi-Power as one of his weapons in the conclusion of the film.
Tokarev TT-33
A Tokarev TT-33 pistol is used by Fai during the shootout at the Y.S Leong's club.
Submachine Guns
Beretta M12
A Beretta M12 submachine gun, concealed under a piano, is used by Wing during the gunfight at the Leong's club.
Sten gun
One of Leong's thugs is briefly seen firing a Sten submachine gun before being shot by Wing.
M1928 Thompson
Ah Lok (Simon Yam) uses an M1928 Thompson without a butt stock and loaded with a 30-round box magazines during the gunfight at Leong's club.
Shotguns
Remington 870 Shotgun
Ah Bee uses a pistol-gripped Remington 870 shotgun with a sawed-off barrel during the gunfight at the crime lord's club. The cap on the magazine tube is the giveaway that it's an 870.
Rifles
M1 Carbine
An M1 Carbine is used by a shopkeeper in an attempt to defend his store from robbery. Later, another M1 Carbine appears in the hands of a gangster working for a local crime boss.
M16A1 Rifle
M16A1 rifles are used by ARVN and American soldiers, as well as Việt Cộng rebels throughout the film. Ah Lok (Simon Yam) is armed with an M16A1 when he attacks the Việt Cộng camp with American soldiers, and Fai (Jacky Yeung) attacks his Việt Cộng captors with a captured M16A1.
Colt Model 653 Carbine
When the main characters attempt to flee pursuing ARVN forces, Ah Lok (Simon Yam) and Fai (Jacky Cheung) use Colt Model 653 carbines with two 20-round magazines taped "jungle style" to defend themselves. Note: In the real world, these variants by Colt were only available after 1973 so any depiction during the time frame between 1964-1973 is anachronistic.
M60 Machine Gun
M60 machine guns appears in two instances. It first is shown as a Jeep mounted weapon when ARVN soldiers rob a jewelery story, and a helicopter mounted M60D machine gun is shown when U.S. special forces attack the Việt Cộng encampment.
M21 Designated Marksman Rifle
An M21 Designated Marksman Rifle is used by U.S. special forces to kill Việt Cộng guards in the watch towers during their assault on an enemy encampment.
Norinco Type 56
Norinco Type 56 assault rifles are used by the Việt Cộng and North Vietnamese soldiers who capture Ah Bee, Fai and Wing. Wing later uses a captured Type 56 to massacre an innocent family when he steals their boat.
Other
M16A1 with M203
South Vietnamese soldiers carry M16A1 rifles with M203 grenade launchers when they chase the three protagonists along a river.
M18A1 Claymore Mine
Used by Lok during they run to the boat.Kill ARVN Force.