The M1 Garand is the main battle rifle carried by US troops in the film.
M1 Carbine
The M1 Carbine is seen in the hands of several US officers.
Lee-Enfield No. 1 Mk III*
The Lee-Enfield No. 1 Mk III* is seen carried by members of the Scots Guard. At the film's beginning, US troops are seen carrying the rifle as well. In reality, these American troops should be carrying the M1 Garand, however there were some instances in the early Italian campaigns (and in the Far East) where US troops were issued Lee-Enfields for logistical reasons.
The Browning M2 HB is seen mounted on US M47 Patton and M24 Chaffee tanks. Some of these tanks are mocked up to resemble German armor.
Browning M2 Aircraft
What appears to be a P51 Mustang does a strafing run on a German foxhole. The P51 was armed with the Aircraft Model of the Browning M2.
Browning Automatic Rifle
German troops are seen in machine gun nests opening fire with the Browning Automatic Rifle. The BAR was primarily used by American forces during the war.
Bren Gun
German troops are seen in machine gun nests opening fire with what appears to be a Bren Gun. In reality, this machine gun was primarily used by British forces during the war, although the Germans did issue have stocks of Brens captured at Dunkirk and issued them to rear echelon units, most notibly French Milice and Ost Battalions.
MG42
When American troops are seen at the harbor, one soldier is seen carrying what appears to be an MG42. In reality, this machine gun was primarily used by German forces during the war.
Submachine Guns
M1A1 Thompson SMG
The M1A1 Thompson is seen in the hands of several US soldiers.
MP40 SMG
German troops are armed with the MP40 throughout the film.
Other
Mk 2 Hand Grenade
The Mk 2 Hand Grenade is also carried by the Rangers. These appear to be prop versions.