Issued to John Rambo (Sylvestor Stallone) by his CIA controllers is a Heckler & Koch MP5A3. He loses the weapon when he is forced to cut away his equipment when his parachute rigging gets caught up during insertion.
Heckler & Koch HK33A2
A Vietnamese soldier is seen armed with an H&K HK33A2 rifle while watching from a tree. It could also be the civilian HK93 rifle but not enough is shown to clarify.
SVD Dragunov
A Vietnamese soldier is seen armed with an SVD Dragunov sniper rifle in a tree. It could be another model of similar shape but based on what is seen, it is an SVD.
AKM
When Rambo first lands in Vietnam, he meets up with Co Bao (Julia Nickson-Soul) who is armed with an AKM. Rambo later picks up a few AKMs throughout he film to dispatch several enemy Vietnamese and Russian soldiers. Vietnamese and Russian troops are widely seen armed with AKMs as well.
Norinco Type 56
While mainly AKMs dominate the film, some chinese Norinco Type 56 rifles are seen in the hands of the Vietnamese, which is accurate. Unfortunately, they are also seen in the hands of some of the Russian soldiers, which is a major inaccuracy.
M60E1
The door gunner of the chopper sent to pick up Rambo is seen firing an M60E1 machine gun and killing several Vietnamese soldiers with it.
M60D (mock up)
When Rambo and the POWs are escaping in the fake Hind D, another chopper flies up and begins firing at them with an M60D which looks to be dressed up to look like a aircraft model DShK heavy machine gun by being fitted with a semi-similair muzzle break and spade grips.
M60E3
When Rambo flies the POWs out of the prison camp in a civilian Aerospatiale SA 330 Puma (mocked up to look like a Hind D by bolting on wings), he lands the chopper and picks up an M60E3 machine gun from the chopper door. He later empties it in the the command center to destroy all the high tech equipment and scare Marshall Murdock (Charles Napier) for betraying him.
Ingram MAC-10
When Co Bao disguises herself as a prostitute to save Rambo, she uses a MAC-10 with a mock-suppressor to fend off the Vietnamese troops. Somehow this film was nominated for a sound oscar despite how Rambo's AK spits out rounds at ~650RPM while her MAC-10 fires at ~1200RPM and both guns have the same report in the film.
RPG-7
Rambo disposes of an enemy boat by pulling an RPG-7 out from under a compartment in the gun boat. The weapon appears to be fitted with a strange shaped training warhead as opposed to the traditional one.
I think this is the same fake RPG-7 that MoviePropMaster2008 wrote about on the Red Dawn page.
M72 LAW
When Rambo crashes his chopper, the enemy helo flies over to confirm the crash. Rambo plays dead until they fly over fires an M72 LAW launcher through the windshield and blows them up. It should be noted that the back blast would have likely killed or wounded all the POWs in the back of the chopper.
Rambo's Survival Knife
While not a gun, we let Rambo's knife stay because, well, he's Rambo and his knife completes him.
Hoyt Archery Rambo compound
Another non-firearm Rambo gets away with, his Hoyt Archery compound bow which has been well know as the "Torque Bow" because of the high explosive arrow tips he fires from it.
Remington 870
A Vietnamese pirate can be seen wielding a Remington 870 shotgun with a wooden forened and folding stock. Rambo (Sylvester Stallone) fires a few rounds at the pirates with the shotgun.
Dual Browning M3 anti-aircraft
An opposing Vietnamese gunboat begins to blow apart the gunboat Rambo is with dual mounted Browning M3 anti-aircraft .50 caliber guns noted by their perferated barrel shrouds.
M16A1
Some Vietnamese troops guarding the boat and docks are seen armed with M16A1 rifles.
M16A1 w/ A2 handguards
A Vietnamese soldier can be seen with an M16A1 fitted with A2 handguards on the boat docks.
MGC M16 Replica
Next to the RPG-7 stored in the boat is an MGC M16 replica rifle.
GE M134 Mini-Gun
Seen mounted on the left side of the fake Hind D is a GE M134 Mini-Gun which is electrically fired by Rambo at the controls and is then manned by one of the POWs who managed to kill a Russian chopper door gunner with it.
Tokarev TT-33
Seen as the side arms of all the Vietnamese soldiers is the Tokarev TT-33, although the Chinese Norinco Type 54 would be more accurate for them to use.
M67 "Baseball" grenade
When escaping the Vietnamese camp, Rambo grabs a bag of M67 "Baseball" Grenades and uses them against the soldiers.
SIG-Sauer P226
The door gunner pulls out a SIG-Sauer P226 pistol and holds it to Colonel Trautman (Richard Crenna) when he tries to stop the chopper from leaving Rambo. It is noted a P226 by its double stack creases on the frame.
M29 81mm Mortar
When Rambo, Co Bao, and the POW run throught the rice paddy field, Vietnamese soldiers drop M29 81mm Mortars across the field at them but don't score a hit.
M1911A1
One of the Vietnamese pirates on the gun boat has an M1911A1 pistol in his holster and puts his hand on it when Rambo and Co Bao enter the boat.