by David Tong
Firearms historian, David Tong, gets the chance to briefly shoot a piece of machine gun history, the Thompson 1928A1 Submachine Gun.
At the outbreak of WWI, he decided to resign from the military and went into the employ of Remington Arms of Ilion, NY. He was instrumental in setting up the now-defunct Eddystone government arsenal that built many hundreds of thousands of Moisin-Nagant rifles for the Imperial Russian government.
However, Thompson’s primary focus was in the development of auto-loading small arms. He became acquainted with a retired USN commander named John Blish, and was attempting to develop a rifle caliber weapon using the so-called “Blish Lock.”
This was a friction lock meant to delay the opening of a bolt when pressures had dropped to a safe level. This was something that Cmdr. Blish had noticed had worked with naval cannon, but miniaturizing it for the use with a rifle was apparently unworkable, as it did not function well with the high-pressures and bolt velocities of our .30-06 standard rifle cartridge.
The use of the Blish lock was then determined by General Thompson to be adequate with the much smaller and less powerful M1911 .45 pistol cartridge, in a relatively small and “light” (ten-pounds empty) selective fire weapon that he called a “trench-broom.”
The nickname was illustrative of the expected use, it was meant to allow soldiers a volume of fire to cut down enemy infantrymen after they had crossed No Man’s Land to eliminate resistance.
The resulting piece was not yet ready for production when the Armistice was signed on November 11, 1918, so the trench-broom became a “sub-machine-gun,” in that it was single man portable and a reduced scale small arm compared to the size and weight of the prevalent tripod mounted, water-cooled medium and heavy machine guns of the era.
The earliest TSMG was the Colt-produced M1921, and with its light bolt and 1,200 rounds per minute rate of fire, could empty its 20-round box magazine in under a second.
The company made alternative magazines, including a 30-round box, a 50-round circular drum, and a 100-round drum.
Thompson 1928A1 Submachine Gun
The later versions of the SMG included the M1928, which began production as a Savage Arms product, that still featured the cooling finned barrel, the Cutt’s muzzle compensator, and selective fire capability (“SEMI,” and “FULL” automatic). Both it and the M1928A1 contain a heavier bolt to reduce the rate of fire to approximately 650rpm, but the 1928A1 lost the iconic finger grooved slanted vertical foregrip in favor of the horizontal grooved fore-end. The US Army bought quantities of the M1928A1 before WWII and these had either the original barrel style with cooling fins, or were plain.
TSMG’s were actually-offered to civilian and police buyers in the 1920s and into the 1930s until the FDR Administration enacted the National Firearms Act of 1934 that essentially provided for mandatory registration and the payment of a $200 tax stamp to purchase or possess any fully-automatic arm or “destructive device” that was open to interpretation.
During WWII, the call by the US military for hundreds of thousands of small portable SMG’s meant that the TSMG was radically simplified to improve production ease and save on raw materials. There were two primary models made.
The M1 model eliminated the Blish lock that didn’t truly add anything to the arm’s durability or function. The final production version, the M1A1, featured a bolt with a fixed firing pin, a welded-on bent sheet metal aperture rear sight, no drum magazine capability, and was full auto only. Neither had the Cutt’s brake, instead a simple front sight mounted on a barrel band flush with the muzzle. The fore-end again was a simple walnut rectangle with horizontal grasping grooves, same as the M1928A1. Neither the M1 nor M1A1 had the ability to accept drum magazines as they were found to be too bulky and heavy for military use.
These later “M1” TSMGs were normally carried by NCOs, along with a 1911 pistol on the belt and thus there was ammunition continuity similar to the arms of other nations for these weapon types. M1s typically had a rate of fire of roughly 500rpm, a far-cry from the original 1,200, for both controllability and economy reasons.
The actual Thompson 1928 A1 Submachine Gun Carbine M1928 that was the subject of this hands on review was manufactured by a colleague of mine who has the requisite BATFE Class 07 SOT licensing. Most of these original upper receivers were torch cut to be un-restorable, and correctly finished with historically-appropriate markings, in black oxide. The lower grip frame and fire control parts are original, as is the buttstock, the Cutt’s brake, and the bolt with the Blish lock.
I had only fired a TSMG once in my life before, while working as a Range Officer at my local rifle club during their annual machine gun shoot held each May. I believe it was an M1A1 but my memory is cloudy on this. This replica 1928 is a much more highly-finished item than the Parkerized WWII guns.
I had received conflicting instructions on how to “control” the recoil of the Thompson. One guy suggested that I simply rest the fore-arm on my left hand as a rest and let the piece move around during recoil, while my colleague suggests the exact opposite, holding it and pressing it firmly against the shoulder and try to hold the muzzle down during a firing string.
I tried both methods and the result was that neither seemed to work all that well to control muzzle rise or shot dispersion. While the bore axis of the bolt and barrel are relatively low, even at the low rounds-per-minute count and eleven pounds loaded weight with the 20-round stick magazine, the geometry of the drop at comb and heel of the buttstock caused rapid muzzle rise. Add to this that the forward pistol fore-grip doesn’t really lend itself to merely resting one’s support hand on or under it necessitated using it as designed which is pulling the barrel back and down.
Short bursts of four or five rounds were practical at up to ten yards, but more than that the climb was too much for me to control. We also had a fifty-round drum magazine available, but the weather was rainy during our test session so we decided we didn’t want to risk damaging this expensive item. Twenty-round magazines don’t last very long if you hold the trigger back.
It was a pleasure to shoot a piece of history that is the Thompson 1928A1 Submachine Gun.