The following guns were used in 20 Million Miles to Earth.
20 Million Miles to Earth (1957)
12 Gauge Double Barreled Shotgun
Confronting the Ymir in his barn, a Sicilian farmer (Sid Cassel) grabs a 12 gauge double-barreled shotgun.
J. Stevens and Company Side by Side Shotgun (Circa 1878) exposed hammers and designed to fire Black Powder shotgun shells - 12 Gauge
The farmer retrieves his shotgun from the barn wall.
Shotgun and lantern in hand, the farmer investigates things.
The local Sicilian police officers wield M1A1 Carbines with folded stocks. During the confrontation with the Ymir in the farmer's barn, Colonel Calder (William Hopper) uses one of these.
M1A1 Carbine - .30 Carbine
The officer to the left brandishes his M1A1 Carbine.
Calder grabs the M1A1 Carbine from the officer and uses it against the beast himself.
While hunting the Ymir in the countryside, one Sicilian police officer has an M2 Flamethrower.
The flamethrower-wielding officer takes up his position as they sight the Ymir.
In a subsequent shot, there is a continuity break when the policeman is replaced with a totally different actor. The new 'actor' is probably a stuntman who knew how to properly operate the flamethrower. As a side note, all it takes is one malfunction to spook most actors when operating a device like a flamethrower. Nowadays films use stunt trained personnel from the beginning when using live incendiary devices like a flamethrower.
Colonel Bob Calder (William Hopper) and a few Italian soldiers use M9 bazookas with face-shields.
Col. Calder wields his bazooka.
A soldier with a bazooka backs up as some rocks hurled by the Ymir falls towards his comrades.
'Twas William Hopper killed the beast!
An Italian army sergeant carries an M1911A1 pistol as his sidearm.
World War 2 issued Colt M1911A1 Pistol - .45 ACP
visible on the left behind Calder.
The soldier on the left of the Bazooka operator holds an M1911 pistol.
Wielded by U.S. Marines who are seen getting off of a helicopter and the Italian soldiers who assist Calder in confronting the Ymir in Rome.
M1 Garand semiautomatic Rifle with leather M1917 sling - .30-06
A U.S. Marine getting off the helicopter holds his M1 Garand.
The Marine in back has an M1 Garand slung over his shoulder.
As the Ymir destroys a bridge, one brave soldier lingers to shoot at him.
Three soldiers shoot up at the Ymir seconds before being squished by falling columns.
Three more soldiers spin around with their M1 Garands after barely avoiding their predecessors' fate.
Smith & Wesson Model 32
Police Commissioner Unte (Tito Vuolo) uses what looks to be a Smith & Wesson Model 32.
Smith and Wesson Model Terrier - .38 S&W
Unte points his Smith & Wesson at the Ymir as Dr. Uhl tries to push it into a cage.
Unte joins Calder in shooting at the Ymir as it attacks the farmer.
Unte calls his flamethrower-wielding man up, Smith & Wesson in hand.
A soldier on a tank fires at the Ymir with a Browning M2 on his tank (but not its main cannon, oddly).
Browning M2HB on vehicle mount - .50 BMG
The Browning M2 on top of the tank.