M16A1s are used by various characters throughout the film. Since this film takes place in the early '70s, the introduction of the 30-round magazine is historically accurate.
M60 machine gun
M60 machine guns are mounted on both Col. Kilgore's (Robert Duvall) choppers during the battle at Vinh Din Drop and the Navy PBR, used by the crew to travel up river.
Add more info to the description and captions to the images so I have more to work with. - Gunmaster45
M1911A1
An M1911A1 is seen on Capt. Benjamin Willard (Martin Sheen) nightstand in hotel bedroom in Saigon at the start of the film. Lt. Col. Bill Kilgore (Robert Duvall) uses one as his sidearm throughout the movie.
M79 grenade launcher
An M79 grenade launcher is used by Roach (Herb Rice) to kill an NVA soldier hiding in the barbed wire during the scene at the Do Lung bridge. Roach had customized his with a tiger-strip paint job.
GE M134 Minigun
A GE M134 Minigun is seen door-mounted on one of the UH-1 Huey choppers during the famous raid scene. Being that the movie was filmed in the Philippines, they also supplied the helicopters which were outfitted with real guns. Since the weapons require no blank adaption to fire, all they needed was lots of blank ammunition to get the guns running.
ZU-23 AA Gun
I guess this is right, gun type was already on the page. If not please correct me. Thanks -Predator20
Based on the shape of the reciever, I'd say it's a Browning M2HB mocked up as the ZU-23 gun, but like you, I don't know that weapon. - Gunmaster45
It's probably not a ZU-23 at all, which has two barrels and is far larger in size, but a Browning mocked up to resemble the DsHK machine gun.