The Thompson Machine Gun




The Thompson Submachine Gun was first used in combat when they were carried by U.S.

Marines in Nicaragua during the Banana Wars. It wasn’t until World War II that the Thompson

Submachine Gun received the nickname Tommy Gun, after it was adopted by the British before the

United States officially entered the war as a combatant on the side of the Allies.

Depending on the model, the Thompson Submachine Gun fired a .45 ACP caliber pistol

cartridge from a detachable 50 or 100 round drum magazine, or a 20 or 30 round metal box “stick

magazine” and had a rate of fire of 600 to 800 rounds per minute. U.S. Navy models were

manufactured to fire at a slower rate to conserve ammunition and make the weapon more controllable

under full automatic fire. The average weight of an unloaded Thompson Submachine Gun was just

under 11 pounds. When loaded with a 30 round magazine of 230 grain .45 ACP ammunition the

Thompson weighed closer to 13 pounds.

Despite the fact that the Thompson was heavy when loaded to the brim with .45 ACP 

ammunition, most of the troops who carried one liked having a “Tommy Gun” in their hands when they

went into combat. Before an ample number of Thompson Submachine Guns were in circulation, Allied

armies made the bulk of these weapons available to specialized personnel such as commandos,

paratroopers and tank crews, before they were issued in larger numbers to infantry divisions and other

front line personnel.

Even though the Thompson was widely used in all theaters of operation, submachine guns had 

their limitations and were not the ideal weapon to have, if you were fighting in terrain where it was

necessary to engage targets at longer distances. Being a handgun cartridge, .45 ACP bullets were

understandably less effective in certain situations than 30.06 or .303 rifle ammunition. However,

the Thompson was effective when fighting in an urban setting, in the jungle, or in forested terrain.

Despite being on the heavy side, the Thompson proved to be one of the most rugged, reliable 

and powerful submachine guns used during World War II. Thompsons were especially handy when

used to spray tree tops to “recon by fire” when trying to kill well concealed enemy snipers. The

Thompson Submachine Gun also proved to be a handy weapon to be armed with, when enemy troops

attacked a fixed U.S. or Allied position, especially at night. Submachine guns were also favored by

troops when it was necessary to spray a cave, or an enemy stronghold, with a large number of bullets,

to insure that there was no further threat to advancing or passing Allied military personnel. The

Thompson was also the ideal weapon for armored vehicle crews to carry, in case they were forced to

dismount and fight as infantry.

During World War II, U.S. and Allied forces used Thompson Submachine Guns that were 

modified to reduce the cost of production and make the weapon more user friendly. One of these

modifications involved replacing the more complicated original rear sight with a rudimentary but

effective sight, that was less time consuming and less expensive to manufacture.

From a mechanical standpoint the major changes between the original Thompson and later

wartime models involved the use of a fixed stock that could not be removed by the operator, the

removal of the Cutts Compensator on the end of the barrel to reduce muzzle climb under firing

conditions, the relocation of the cocking handle from the top of the receiver to the right side of the

receiver and the adoption of a straight blow back design to facilitate firing the weapon. Wartime M1

and M1A1 Thompson Submachine Guns were also intended to be used with 20 and 30 round metal box

(stick) magazines. Drum magazines and 20 round stick magazines were issued early in the war and

were eventually replaced by 30 round “stick” magazines.

Spare 50 round drum magazines for the Thompson were carried in a well made cotton canvass 

pouch. A canvass ammunition pouch that was attached to an adjustable canvass pistol belt held five

twenty round magazines. Thirty round magazines were carried in a pouch that was designed to hold

three magazines. Twenty and thirty round magazines were also carried in other canvass bags and were

carried tucked into belts, or in field jacket pockets. Some combat veterans who carried a Thompson

sometimes carried one magazine loaded in their weapon and one or two stuffed in their back pocket.

This was done to lighten their load and because an experienced soldier could do a great deal of damage

with 60 or 90 rounds of .45 ACP ammunition, especially in a submachine gun that could be fired in

short bursts, or in the single shot mode. This was accurately portrayed on the TV Show Combat, when

actor Vic Morrow playing Sergeant Chip Saunders, usually carried a minimal number of spare 30 round

magazines inside his field jacket pocket and not in an ammunition pouch on his pistol belt. This was

also verified to me by a WWII combat veteran, who served in the Pacific and often carried a spare

magazine for his Thompson in his back pocket, when he went on certain patrols. He did so when it was

far too hot and humid in the jungle, to be weighed down with an exceptionally heavy combat load.

The U.S. Navy was the first branch of the service to notice the merits of the submachine gun

and placed an order for Model 1928 Thompson sub machine guns. The U.S. Army soon followed and

officially adopted the M1928A1 in 1938 as a standard issue Submachine Gun .45 Caliber. The M1 and

M1A1 appeared later in the war.

In addition to its graceful lines and rugged appearance, the Thompson Submachine Gun had a

tremendous reputation that was cloaked in a great deal of history and nostalgia, because it had been

used by armed professionals and gangsters for several decades. It should also be noted that since all

firearms required the proper cleaning in the field, those who liked carrying a Thompson did not mind

the maintenance chores that were required to keep their submachine gun operational. Even though a

Thompson Submachine Gun and a decent supply of loaded magazines was heavy to carry, it was well

worth the effort to be armed with a Thompson when it came time to pull the trigger in combat. In fact,

the weight of the Thompson kept the recoil to a minimum and made it possible to accurately and more

easily fire this weapon.

For various reasons a Thompson that provided reliable service was often treasured by the men

who were lucky enough to carry one, especially when submachine guns were in short supply. Even

when the lighter M3 Grease Gun became available, many American soldiers and marines preferred

the Thompson, over the submachine gun that looked more like a mechanics tool than a finely crafted

firearm. Over 1.3 million M1928A1, M1 and M1A1 Thompson Submachine Guns were supplied to

Allied forces during World War II. Thompson Submachine Guns went on to serve in The Korean War,

with specimens also serving in The Vietnam War.

Reference sources:
Military Small Arms of the 20th Century by Ian V. Hogg and John Weeks.
U.S. Infantry Weapons of World War II By Bruce N. Canfield.
Infantry Weapons of World War II By Jan Suermindt.
Guadalcanal Marine By Kerry L. Lang.
Weapons of the Navy SEALs by Kevin Dockery.

About the author: Nick Jacobellis is a Medically Retired U.S. Customs Agent and a former NY police officer who was physically disabled in the line of duty while working undercover as a federal agent. To date, the author has published over 205 magazine articles and nine action-packed nonfiction, historical fiction, and fiction books: Controlled Delivery Books One and Two, The Frontline Fugitives Books I, II, III, and IV, Buck Banderas U.S. Marshal Books One and Two and A Special Kind of Hero. These books have received 5 Star reviews and are available on (US), and (UK). He was born and raised in Flatbush section of Brooklyn NY and has an BS Degree in Police Science from John Jay College of Criminal Justice.

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