Them!

The weapons seen in this 1954 movie are:

M20 "Super Bazooka" (3.5" Rocket)

Used by U.S Army Soldiers.

M20 "Super Bazooka" 3.5"

M1 Flamethrower

Used by U.S Army Soldiers.

Schematical drawing of M1A1 Flamethrower

M1928 Thompson

Used by the Police and the Soldiers

M1928 "Tommy Gun" .45 ACP with 50-round drum magazine, made famous through countless classic gangster movies

Peterson's revolver

State Trooper Sgt. Ben Peterson (James Whitmore) uses this holstered revolver to shoot at a giant ant.

Peterson shoots at the ant.

Peterson comes to the conclusion his service revolver isn't doing much good.

Machine gun

After his service revolver fails to slay the giant ant, Peterson runs and gets this from his patrol car. Needless to say it packs a bit more of a punch. This may be a Thompson.

Peterson locks and loads.

Peterson gets medieval on the ant's abdomen.

Snub-nosed revolver

A snub-nosed revolver is found by Sgt. Peterson in the destroyed camper at the beginning of the movie.

The revolver lying on the floor.

Sliding a pencil into the barrel, Peterson picks the revolver up to examine it.

Lever-action rifle

A lever-action rifle, described as a 30-30, is found at Gramps Johnson's store with the barrel bent in half.

The rifle lying on the floor.

Peterson examines the weapon as Blackburn looks on.

Captain Edwards examines the gun.