The M1928 Thompson is used by Jack Driscoll (Adrien Brody), First Mate Ben Hayes (Evan Parke), Lumpy the Cook (Andy Serkis), Bruce Baxter (Kyle Chandler), and various members of the crew of the S.S. Venture during the mission to rescue Ann Darrow (Naomi Watts). Jimmy (Jamie Bell) uses a Thompson to shoot the crickets off of Jack when in the insect pit. The Thompsons seen in the film have the classic 'gangster' configuration; vertical foregrips, Cutts compensators, charging handle on the top, and high-capacity 50rd. drum magazines.
It would be a task to correctly identify if the Thompsons used in the film are 1921AC (compensated), 1928 "overstamp" from 1921 Colt, or 1928A1's with vertical grip added for the film to give them the earlier look. However, it is logical to assume that these are actually WWII M1928A1's with make-overs in order to give the appearance of the earlier pre-war Colt guns. Also, the M1928 Thompson was already in production and was widely available during the time period the film was set in (early 1930s), so the use the M1928 Thompsons by the crew of the Venture is authentic to the period of time.
Mauser Gewehr 1898
Another weapon used by the crew of the Venture is the German-made Mauser Gewehr 1898 bolt-action rifle. Though firing a more powerful round (7.92x57mm Mauser), they tend to be less effective in the film overall than the rapid-fire Thompsons, possibly due to the Gew 98's straight bolt handle (which slows down reload time compared to the rate of fire of a bolt-action rifle that has a turned-down bolt handle), "cock on opening" bolt-action and five-round magazine. Carl Denham (Jack Black) is also seen using a Gewehr 98 rifle as a club against the giant insects in the chasm.
M1911
The second mate of the Venture, Ben Hayes (Evan Parke) carries an M1911 pistol during the mission to rescue Ann.
Luger P08 "Artillery"
The skipper of the S.S. Venture, Captain Englehorn (Thomas Kretschmann) is seen using a long-barreled Artillery model Luger P08 pistol, shooting a Skull Island native with it just as the native is about to kill Carl Denham (Jack Black).
M1917 Enfield
Several U.S. Army soldiers can be seen using the M1917 Enfield bolt-action rifle alongside soldiers armed with Springfield M1903 rifles.
M1903 Springfield
Several U.S. Soldiers can be seen armed with M1903 Springfield bolt-action rifles. At the end of the movie, three soldiers can be seen posing for a photo with their Springfield rifles.
Browning Automatic Rifle
In the extended edition of the film, a soldier armed with a Browning Automatic Rifle in the back of a military truck is telling his fellow comrades what they will do to Kong before the giant ape runs into the vehicle, and smashes it into a wall. Note that the gun is a BAR M1918A2 with bipod removed, which wouldn't have existed at the time of the movie. A BAR M1918 would have been correct.
Smith & Wesson M&P Revolver
The Smith & Wesson Model 10 can be seen in the holster of a cop Jack Driscoll shoves past to get into the Empire State Building.
Browning M2 Aircraft Heavy Machine Gun
The Browning M2 Aircraft heavy machine gun can be seen mounted on Navy-flown Curtiss Falcon biplanes as the primary armament.
Lewis Gun
During the climax of the movie, the Curtis Falcon biplanes that attack Kong on the Empire State Building are fitted with Lewis guns for the observer/tail gunner. The version used on the biplanes are air-cooled and lack the thick, water-filled sleeve around the barrel.
Browning M1919
In the scene where Kong is pursued from Central Park to the Empire State Building, U.S. Army soldiers are seen firing on the giant ape with a Browning M1919 machine gun mounted in the back of a car. Some are also seen mounted on the top of U.S. Army cars facing the Empire State Building. The model shown, the M1919A4, is somewhat anachronistic for 1933 however.
Enfield 13-pdr 9-cwt Mk I, 3
While Kong is being pursued through New York City, U.S Army soldiers fire at him with QF 13 pounder 9 cwt, 3 mounted on several military trucks. This was a First World War adaption of obsolete 13 pounder cannon as air defense weapons, hence the high angle mounting shown on the truck. The weapon is of three inch (76mm) calibre; the "9-cwt" indicating the barrel/breech assembly weighs nine hundredweight and differentiates this model weapon from other "thirteen pounders".
Unknown Harpoon
When Kong is attacking the crew of the Venture during their attempt to capture him, Captain Englehorn (Thomas Kretschmann) shoots Kong in the leg with a harpoon gun of unknown make and model.
Weapons Platforms
The Fighter Planes used to attack Kong in the film were Curtiss Falcons.