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.
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.
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.
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.
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.
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.
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.
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.
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.
