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.
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.
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.
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 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.
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.
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.
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.
M60 machine guns appears in two instances. It first is shown as a Jeep mounted weapon when ARVN soldiers rob a jewelery store and later in the hands of Việt Cộng at their encampment.
The M79 grenade launcher is carried by ARVN soldiers, who use use them to fire tear gas grenades at anti-war protesters. American soldiers fighting off a Viet Cong ambush are also briefly shown using them.
South Vietnamese soldiers carry M16A1 rifles with M203 grenade launchers when they chase the three protagonists along a river. The weapon is anachronistic since the movie is set roughly between 1967 and 1968, while the M203 did not enter American service until 1969.
