Colt Model 1921 Thompson Class III/NFA C&R Fully Transferable Machine Gun with U.S.M.C. Contract Trigger Housing and Provenance Documentation

Description:
A once-in-a-generation Colt Thompson with extraordinary factory provenance, this Model 1921AC is described as the last known Thompson submachine gun ever transferred out of the Colt factory. Hidden away at Colt from its 1922 manufacture until its discovery by Charles Reed Knight Jr. in 1990, it is being offered publicly for the first time since leaving Colt—an exceptional opportunity for advanced collectors of American automatic arms, Colt history, and Thompson submachine guns.

• Offered as the very last Colt Thompson submachine gun to have transferred out of the Colt factory
• Remained hidden away at the Colt factory from its original manufacture in 1922 until 1990
• Serial number: 11943
• Model: Colt Model 1921 Thompson, completed in 1921AC configuration
• Historically significant as one of the first truly practical pistol-caliber automatic weapons to reach the market
• Important to the story of American arms development and a prime example of its generation of submachine guns
• Built with the classic early Thompson combination of machined steel and walnut
• Known for close-quarters firepower and iconic 20th-century design
• Early Colt-made Thompsons are especially prized for their exceptional fit and finish, including:
  • Deep, bright bluing
  • Tight-fitting components
  • Exceptionally smooth action
• The original Model 1921 release was ahead of its time and initially faced market resistance
• Original price was $200, equivalent to approximately $3,000 today when adjusted for inflation
• The United States Marine Corps became the first American military branch to give the Thompson a proper trial
• Thompson models later became key weapons for the U.S. military and foreign allies through and beyond World War II
• Equally famous and infamous as the “Chicago Typewriter” during America’s “Public Enemy” era, used on both sides of the law
• Listed on page 980 of Herigstad’s “Colt Thompson Submachine Gun” as a 1921A
• Herigstad listing notes a possessor of Knight Industries of Vero Beach, Florida
• Herigstad entry further states: “Receiver came from the Colt factory collection without lower Frame (sic) and rear sight. Appears to be in new and unused condition. 1995 GH”
• Includes a letter on Institute of Military Technology letterhead dated February 4, 2026
• Letter is signed by Charles Reed Knight Jr.
• Charles Reed Knight Jr. is the owner of the Institute of Military Technology and namesake of Knight’s Armament Company
• In the letter, Knight states that, as owner of the Institute of Military Technology, he is consigning this special M1921AC Thompson Submachine Gun for sale at Rock Island in their May 2026 Premier
• Knight describes the gun as “a particularly historical Thompson” due to its detailed provenance, how he acquired it, and the journey it took before reaching him
• Knight states that serial number 11943 has been in his museum for many years
• Knight states he is releasing it for public sale for the first time since it left Colt’s factory
• Knight states this is the last known Thompson to have been transferred out of Colt
• Knight states this will be the only time it has ever been offered for public sale
• Knight explains that he had done business with Colt Industries many years ago and, as part of the deal, convinced Colt to transfer some firearms from their factory to him as payment
• After logistics were worked out, Knight had the opportunity in 1990 to walk through the original Colt factory and search for historically valuable arms
• Knight states he spent considerable time methodically combing through the facility
• During the search, he encountered boarded-up rooms and abandoned areas of the Colt factory
• Knight believed these untouched areas might contain some of Colt’s best historic treasures, describing them as miniature time capsules
• In one abandoned area, Knight tore down wooden barricades leading to a workshop about the size of a small closet
• In that workshop, he discovered a stash of historically significant arms that remain among the most intriguing in his collection
• Items Knight states he found in that room included:
  • Thompson upper receiver serial number 11943
  • Thompson lower receiver number 41, said to be the first Thompson made at Colt as a pattern example for the M1921 contract
  • Serial number 2 of the 6 mm Browning Machine Gun “Potato Digger”
  • The prototype 1895 Browning “Potato Digger” made to contest Sir Hiram Maxim’s litigation over machine gun patent infringement
  • An original factory-cutaway commercial 1919 BAR
• Knight states each of the guns pulled from that workshop had been left completely untouched through time
• He describes the room as a perfect snapshot of Colt during the height of its manufacturing prowess at the turn of the century
• Knight states the arms had been “clearly hidden away by a long dead employee” who understood their historical significance
• Knight states he was the first to uncover them after decades of storage in the workshop
• Knight notes that as he wiped away years of dust, he realized he may have been the first person to handle Thompson serial number 11943 in 68 years
• Knight states the gun had been preserved in that room since original manufacture
• Knight reflects that these arms might still be sitting in the original Colt factory workshop today had he not discovered them during the 1990 trade deal
• Knight states he is offering this Thompson to the open market for the first time since it was manufactured at Colt in 1922
• Knight states it was never moved out of Colt’s possession until he discovered it in 1990
• Knight has kept the gun in his museum, the Institute of Military Technology, since acquiring it
• Knight describes it as “truly a historic artifact” and a time capsule of Colt during the peak production era of some of its most iconic arms
• Also includes a photocopy of the original NFA Form 3
• NFA Form 3 shows this arm by serial number as a direct transfer from Colt to Knight
• This Model 1921 was the last Thompson submachine gun to leave the Colt factory
• It transferred directly from Colt to the Institute of Military Technology for display and preservation
• The Institute of Military Technology was under the same roof as Knight’s Armament Company
• The Thompson remained there until transfer to Rock Island Company
• Described as brand new to the market
• Described as the only Thompson known to have passed through the 20th century and into the 21st century with only a single owner besides the Colt factory
• Completed in 1921AC configuration
• Blade front sight installed on the Cutts-marked compensator
• Flip-up Lyman rear sight graduated to 600 yards
• Proper witness marks on the finned barrel and receiver
• Receiver markings are proper for the model
• Left side of receiver features:
  • “MODEL OF 1921.” nomenclature
  • Five-line address
• Top of receiver features the Thompson “bullet” logo
• Right side of receiver features:
  • Auto-Ordnance address
  • Seven-line patent markings
• Trigger housing is numbered “4959” on the stock rail
• Trigger housing features knurled controls
• Per page 510 of Herigstad’s listing, trigger housing number 4959 tracks to a 1921AC that was part of the first U.S.M.C. contract in 1926
• That U.S.M.C. contract gun later passed through:
  • China
  • Nicaragua
  • Paris Island
  • San Diego
  • Quantico
• Internals remain in 1921 configuration
• Fitted with an “S” marked Blish lock
• Other internal components are not marked
• Fitted with a pair of pistol grips
• Fitted with a quick-detach buttstock
• Buttstock bears a small “anchor” stamp below the mounting iron
• Includes one Seymour Products 20-round stick magazine
• Collector appeal is exceptional due to its combination of:
  • Last-known Colt factory transfer status
  • 1922 Colt manufacture
  • Direct Colt-to-Knight documented transfer
  • Institute of Military Technology provenance
  • Charles Reed Knight Jr. letter
  • NFA Form 3 documentation
  • Herigstad publication listing
  • Long-hidden Colt factory “time capsule” discovery story
  • First public offering since leaving Colt
  • Iconic Model 1921 Thompson historical importance
• A landmark Thompson for the most advanced collections, with provenance and historical context that set it apart from standard Colt Thompsons and elevate it to true museum-grade status.

Condition

Excellent overall, retains 95% plus bright original blue finish, with light edge wear, some minor surface oxidation, handling marks, and sharp markings and edges in the overall. The Cutts compensator shows some slight rotational play on the barrel. The included magazine does not consistently engage the hold-open, but the Thompson itself is mechanically excellent. An important milestone in the history of the Colt Thompson, connected to both the rise of the Thompson in the hands of the Marine Corps and the end of the line at the Colt Factory, worthy of a place in an advanced collection of NFA items or American firearms. NOTE: This weapon is a National Firearms Act (NFA), fully transferable Class 3, which is registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives, (BATFE) that is classified as a “Curios or Relic” as defined in 27 CFR, 478.11. These weapons are still subject to the provisions of 18 U.S.C. Chapter 44 and 27 CFR part 479.

Rifle Caliber: .45 ACP
Manufacturer: Colt
Model: 1921
Serial Number: 11943
Barrel Length: 10 1/2 inch fluted
Condition: The bore is bright with crisp rifling.

Price: $149,999.99