The following guns were used in The Giant Behemoth (a.k.a. Behemoth the Sea Monster).
The Giant Behemoth (1959)
12 Gauge Double Barreled Shotgun
A farmer who encounters the Paleosaurus is seen using what appears to be a 12-gauge shotgun.
The farmer and his son rush outside.
Taking aim at the Paleosaurus.
Lee-Enfield No.4 MkI
British soldiers in the film use Lee-Enfield No.4 MkI rifles.
Lee-Enfield No.4 Mk.I - .303 British.
A soldier assisting in evacuating London knocks on a person's door while holding his Lee-Enfield No.4 MkI rifle.
A soldier helps people into a truck, his Lee-Enfield No.4 MkI rifle slung over his shoulder.
Two soldiers manning Bren light machine guns fire at the Paleosaurus during the monster's rampage through London. One soldier uses the earliest Mk.1 model, while the other uses a later Mk.2.
The soldiers fire at the Paleosaurus from behind a sandbag wall with Bren Guns. The soldier closest to the camera uses an original Bren Mk.1, while his comrade behind him is armed with a later Mk.2 (both weapons use a different design for the rear sight, clearly visible here).
Closeup of the Bren Mk.1 used by the first soldier, showing the older-style rear sight.
The British sergeant commanding the Bren gunners has an Enfield No.2 revolver on a lanyard.
The sergeant fires his Enfield over the heads of his two gunners.