In late February of 1942, a prototype of the Savage redesigned Thompson Submachine Gun was ready to be submitted to the Ordnance Department for testing and approval. The Savage Corporation had just conducted their own 10,000 round endurance test, which the new weapon successfully passed. The Savage Corporation told Auto-Ordnance that they were submitting the redesigned Thompson “without any claims for compensation, reimbursement, royalty or patent interest”. The new Thompson was sent to Aberdeen Proving Ground for testing and evaluation. The Aberdeen trials of the new Thompson were rather brief and concluded on 21 March 1942. The Aberdeen report stated that “The overall consideration of the mechanical functioning leads to the judgement that the gun as a mechanism is equivalent or superior to the M1928A1”. After a few government recommended alterations to the prototype were made, the new Thompson was recommended for adoption as Submachine Gun, Caliber .45 M1, at an Ordnance Committee meeting held on 24 March 1942. At the same meeting it was recommended that the 1928A1 be reclassified as Limited Standard. On 25 April 1942, the Ordnance Committee approved the recommendation for adoption of the M1 Thompson.

The Stevens Company’s chief designer Nicholas Brewer, and Savage engineer John Pearce were credited with designing the new Thompson. The M1 model had no provisions to use the drum style magazines. It used the same box style magazine as the 1928A1 model. Savage had estimated the cost of producing an M1 model to be $4.36 for material and $6.94 for labor with 175% in overhead. The total cost for Savage to manufacture an M1 would be $23.44. On 24 February 1942, Savage agreed to a contract to manufacture the M1 model for Auto-Ordnance at a cost of $36.37 per unit, providing Savage with a profit of $12.93 per gun. Auto-Ordnance in turn charged the U.S. Government $43.00 for an M1 model. The price varied slightly from contract to contract.

One of the major design differences between the M1 Thompson and the earlier 1928A1 model was that the M1 used a straight blowback design, eliminating the controversial bronze “H” lock. This allowed the receiver to be redesigned for easier manufacture. The bolt assembly was a very simple one-piece block of steel. The inside of the M1 upper receiver simply had a rectangular channel milled into it to accommodate the bolt. The internal felt oiler of the earlier 1928 model was considered unnecessary and thus eliminated in the M1 design. The cocking handle and slot were moved from the top of the receiver to the right side. An enlarged takedown notch was cut in the slot to allow the handle to be easily removed for disassembly (after the receiver has been separated from the frame). Since the drum style magazines had proven unsuitable for military use, the M1 series receivers were not designed to utilize them. The lateral grooves on the sides of the magazine well for accommodating the drum magazine were eliminated.

Like the 1928 and 1928A1, the early M1 Thompson used a separate firing pin and spring, that was the same as the ones used in the earlier models. A separate hammer was also used but the hammers for the M1 were configured differently than that of the 1928 and 1928A1 models. The 1928 series hammers were a triangular configuration, while the M1 hammers were crescent shaped.

Both the recoil spring pilot rod, and the buffer were redesigned for the M1 series Thompson receivers. The pilot rod for the recoil spring was simplified for easier manufacture, and was held in place by the new style buffer. The M1 buffer assembly consisted of a fibre plate secured between two metal plates. The buffer was a substantial improvement over the simple fibre disc used in the 1928 series Thompsons. The M1 pilot rod and buffer also made disassembly and assembly of the weapon much easier, and lessened the possibility of damaging the recoil spring in the process. The pilot rod could be removed and installed through the rear of the receiver once the buffer was removed.

The M1 featured a smooth, unfinned barrel that was similar to the one fitted to the late 1928A1 models, but the muzzle end was not threaded for fitting a compensator. A simple blade style milled sight was fitted and pinned to the muzzle in place of the compensator.

Early M1’s were assembled using the same uncheckered “paddle” style rocker and safety levers that were used on the U.S. 1928A1 model. The magazine latches on many M1 and M1A1 weapons were the same style as the 1928 and 1928A1 type that had a raised area for securing a drum magazine. Since the M1 series would not accommodate a drum style magazine, the magazine latch was later redesigned, and the raised area on the latch was eliminated.

The pistol grip was reconfigured to fit the redesigned M1 trigger frame, and the stock was redesigned as it was now semi-permanently attached directly to the frame with screws. The contour of the stock also differed from the earlier 1928 and 1928A1 design. The stock’s buttplate was also simplified, but retained a spring-loaded trap door for storage of a larger cylindrical oil bottle. The early M1 stock came from the factory without the reinforcing cross bolt installed. The cross bolts were not included until mid 1943 on the M1A1, although most M1 models had their stocks upgraded to include the cross bolt. The standard military horizontal style foregrip was installed on all M1s.

One of the distinctive features of both the M1 and M1A1 guns were their breech bolts, that had been redesigned to have two sear notches machined into them, so that the weapon’s safety could be applied when the bolt was forward on an empty chamber. The 1928 and 1928A1 bolts had only one notch machined into it, and the safety could not be applied when the bolt was closed. Several accidents had been reported with earlier 1928 and 1928A1 models when the weapon was carried with a loaded box style magazine and the bolt closed on an empty chamber. If the weapon was accidentally dropped on its butt, inertia would allow the bolt to travel rearward far enough to pick up a round from the magazine, but often not far enough to engage the sear (that would have held the bolt rearward). The bolt would begin to move forward and chamber the round. The result was usually an accidental discharge of the weapon.

Note; some very early M1 Thompson bolts were manufactured with only one sear notch. An Ordnance Department directive ordered that all one-notch bolts be deemed obsolete, and be replaced with the two-notch bolts as they became available.

While in July of 1942, Savage had turned out 48,000 M1 guns, Auto-Ordnance was struggling to meet its scheduled production mark. The assembly line conversion from the 1928A1 model to the M1 in July through October of 1942, caused serious production setbacks at the Auto-Ordnance plant in Bridgeport. Contributing to the production delays were problems in deliveries of materials, equipment and tooling authorized by the government for M1 production.

After the M1 production finally commenced at the Bridgeport plant, more problems were encountered. The Springfield Ordnance District refused to accept any of the Auto-Ordnance manufactured M1’s because their full-auto cyclic rate exceeded the 860 rounds per minute Ordnance Department specification. Officials from Washington, the District Ordnance office along with Auto-Ordnance engineers conducted studies and tests, all failing to provide a correction for the condition. Finally on 9 December 1942, official notice from the Ordnance Department’s office in Washington gave the district permission to waive the rate of fire requirement and accept the Bridgeport M1 guns. In the interim, identical M1 Thompsons being produced at Savage were being accepted in large quantities by the Rochester Ordnance District without any problems.

The rear sight that was first installed on the M1 was the same simple unprotected “L” style that was also installed on late manufacture 1928A1s. This design proved to have several flaws and was replaced by a similar sight, but with protective side ears added. On 29 June 1942, a letter was sent from Auto-Ordnance to Savage requesting a few changes in a contract originally dated 24 February 1942. One of the changes proposed was to the rear sight. Savage agreed to the changes as long as they conformed to Auto-Ordnance drawings 42-53 for the front sight and A42-86 (protected rear sight). Auto-Ordnance accepted the proposed supplement to the original contract on 17 July 1942. The new sight first appeared on the Savage Arms M1 Thompson in the high 137,000 serial number range. All of the Subsequent M1 and M1A1 models were fitted with new “protected” style sight. The drawing number for the new sight was B147717.

A few of the M1 side-protected style “L” sights have been noted on 1928A1 models depicted in Army manuals. Two such weapons were also documented in the author’s database. The protected rear sight was introduced after the 1928A1 production run had concluded. A protected type of “L” sight fitted to a 1928 model was most likely the result of the weapon going through an Ordnance Department rebuild program.

While Lyman manufactured most of the “L” style sights, Savage, Auto-Ordnance and the H.L. Judd Company manufactured the improved model with side protectors. Manufacturer’s markings noted on the second design sights are either AOC or J, but the majority of them appear to be unmarked. The rebuild guidelines of the Ordnance Department required that all rear sights without protective side ears would be replaced with rear sight drawing number B147717.

There were approximately 285,480 M1s manufactured by Savage Arms and Auto-Ordnance, Bridgeport. Savage Arms manufactured the vast majority of the early M1 model.

This article was excerpted in part from the book “American Thunder, the Military Thompson Submachine guns”. The book is now available from Moose Lake Publishing 207-683-2959

These early Savage Thompsons were very much like the Colt 1928 Navy model, featuring a finned barrel fitted with a Cutts compensator, as well as a finely checkered actuator knob, safety and rocker levers. The early Savage guns also featured a vertical foregrip. As per their contracts with A-O, Savage was not permitted to place their name on the Thompsons that they manufactured. The only way to identify a Savage manufactured 1928 or 1928A1 Thompson is by the S prefix on the serial number. All parts manufactured by Savage were also marked with a letter S. Parts manufactured by Savage’s sister plant, J. Stevens, were marked with a block style letter S. Savage and Stevens manufactured virtually every part for the gun except for various screws and springs. All WWII Savage guns were originally assembled at the factory with Savage (S) or Stevens (S) marked parts.

While the Colt Thompsons were blued, the Savage guns were finished by a process called Du-Lite which was a black oxide type III finish. When this finish was applied to a sandblasted surface it had a flat-black appearance. When applied to other surfaces that have not been sandblasted, it had a low luster blue appearance. The outside surfaces of the trigger frames and receivers were sandblasted on Savage Thompsons prior to the Du-Lite finish being applied, resulting in a flat black color. The inside of these components will appear a dull blue color as will the barrel and all other steel parts and components.

The British Contract Savage Model of 1928

The early 1928 Thompson guns manufactured for the British contracts were marked with a very small British inspector’s stamp placed on the receiver and/or the barrel. The guns were purchased directly from the Auto-Ordnance Corporation. The British contract guns were all fitted with the Lyman adjustable rear sight, and a vertical foregrip. The early one-piece flat-machined ejector was fitted to the early guns as well as the early style (2nd design) Cutts compensator. Thompsons fitted with a vertical foregrip came from the factory with only one sling swivel. This swivel was located on the bottom of the buttstock. British armorer’s often relocated the sling swivel to the top of the stock and added a swivel to the side of the foregrip. There were no U.S. or A1 markings on British contract guns. The British purchased 108,000 Thompsons and a large number of spare parts before the enactment of the U.S. Lend-Lease program. In the first contract the British paid $175.00 for each Thompson they purchased, the price was lowered in subsequent contracts. The very early Savage 1928 models shipped to the British had Auto-Ordnance’s New York, NY address roll marked on the left side of the receiver at the rear.

The Savage Commercial Model of 1928

During Savage’s production of the Thompson, the Auto-Ordnance Corporation sold some of the early 1928 model guns to law enforcement agencies. These Thompsons were exactly the same as the British guns described previously, except there were no British (or U.S.) military proofs or markings. It has been a common belief among many collectors, that the Savage “Commercial” guns were equipped with Colt “nickel” internal parts. A close study of these guns reveals that most of them were actually fitted with blued Savage internals. Most of these guns went to police departments where they saw rather limited use. When encountered, the police guns are generally in much better condition than the weapons that saw military service. Most of the “Commercial” model’s receivers were marked with Auto-Ordnance’s New York address. These guns did not have the cross-bolt added to the stock, as that was strictly a military upgrade.

The Savage Model of US 1928A1 (Early Production)

The letter “U.S.” began to appear on the receivers of 1928 model Thompsons after the Lend-Lease Act was passed in 1941. A provision of the act required that all weapons supplied to the allies through the program be U.S. marked. The Thompsons furnished through Lend-Lease were the same as those issued to U.S. forces.

The first U.S. 1928A1 model Thompsons accepted by the United States Ordnance Department were equipped with a Lyman adjustable rear sight and finned barrel. Virtually all military contract Thompsons destined for U.S. service were equipped with horizontal foregrips, although a few of the earlier “Limited Procurement” weapons were equipped with vertical foregrips. All M1928A1 model Thompsons were fitted with the milled front grip mount. Although a few early military Thompsons had the one-piece machined ejectors, most of the U.S. contract guns were equipped with the new three-piece riveted style. The military wood stocks and foregrips on the weapons were of a slightly lesser quality than had been seen on Colt and early Savage “Commercial” guns. Most of the early manufacture U.S. military contract Thompsons had the checkered actuator, safety and rocker levers. Subsequent production saw the elimination of the checkering on the rocker pivot levers, and eventually the safety lever, but the uncheckered actuators did not appear until later in the production run. The milled sling swivels were fitted on these guns.

A few early Savage military contract Thompsons were fitted with the rare 3rd design muzzle compensator that had the Thompson “Bullet” logo stamped on top of the device, and was not marked with the Auto-Ordnance name. Later manufacture Savage M1928A1 Models used the common “military” (4th design) Cutts compensator that featured the “Bullet” logo on the left side and the Auto-Ordnance name roll marked on the top of the unit.

Virtually all U.S. military contract M1928A1 models will have the Auto-Ordnance Bridgeport, Connecticut address roll marked on the right side of the receiver near the center. The patent numbers were marked on the right side at the rear of the receiver. Also stamped on the receivers of Savage Thompsons was the Army Inspector of Ordnance’s initials, as well as the Ordnance Department “flaming bomb” acceptance stamp. Savage guns also were marked with the initials GEG, of George E. Goll, Auto-Ordnance’s chief inspector.

The U.S. 1928A1 (2nd Variation)

The second variation of the M1928A1 Thompsons was fitted with the rudimentary fixed “L” type sight and finned barrel. The fixed “L” aperture style sight was first installed on the M1928A1s manufactured by Savage during contract number G-14 dated 24 February 1942. The contract was for 400,000 weapons. All subsequent M1928A1s were fitted with the “L” sight. The Ordnance Department felt that the M1928A1 Thompson needed a rugged military style sight with a large aperture for rapid target acquisition. Many of the aforementioned guns generally were equipped with the uncheckered safety and rocker levers, but will often have checkered actuators.

The “L” Sight

At an Ordnance Committee meeting held in December of 1941, it was suggested that a much simpler “L” type of sight replace the complicated Lyman adjustable rear sight on the Thompson. The new sight was better suited for a military application, and would help expedite production of the Thompson. The fixed “L” sight had a .125 inch aperture sighted for a 100-yard range, a second notch was cut into the top of the sight leaf for a 250-yard range. The new “L” aperture style sight was riveted to the receiver in the same manner as the early adjustable model. Lyman also manufactured many of the “L” type sights for Auto-Ordnance and were so marked. The same style of sight was used on early M1 models. The unprotected sight proved to be very easily damaged or bent and would often snag on brush and clothing. A later design provided side ears on the sight for protection of the vertical leaf. The “L” style sight began to appear on the Savage manufactured M1928A1’s at approximately the S-400,000 serial number range.

The U.S. 1928 A1 (Late Production)

The Auto-Ordnance Corporation and Savage had a difficult time keeping up with the ever-increasing demand for the Thompson. To increase production they had to either procure more machine tools and increase the work force, or simplify the parts where possible, for easier manufacture.

There were still a few amenities on the 1928 Thompson that could be eliminated in order to expedite the weapon’s production. After the complex Lyman rear sight, the next elaborate feature of the Thompson to be eliminated for the sake of production was the finned barrel. The U.S. Ordnance Department felt that the open bolt feature of the Thompson design provided enough cooling effect to prevent most premature “cook-off” of cartridges, and felt the barrel’s radial cooling fins were not needed. The smooth barrels began to appear on Savage M1928A1’s at approximately serial number S-500,000.

Late manufacture M1928A1 Thompsons were still equipped with the uncheckered, paddle style safety and rocker levers. The checkering feature was eliminated from the actuators on the late M1928A1 models. Many of the late guns were still fitted with milled style sling swivels.

Although most military 1928 Thompsons encountered today will have a reinforcing cross-bolt in the buttstock, the bolt was added after the gun left the factory. The purpose of the cross-bolt upgrade was to prevent the stocks from cracking. The cross-bolt upgrade campaign began after production of the 1928 model had ended.

The first Thompson M1928A1 models were sold to the U.S. government for “$225.00 minus 10%” which calculates to $202.50 per weapon. An additional $2.50 was added for greasing and packing costs. The price paid by the U.S. Government varied from contract to contract but steadily declined from 1941 until the end of production. The price paid by the U.S. Government for a M1928A1 had been reduced to only $70.00 when the new M1 model was introduced in July of 1942. A spare parts kit for the M1928A1 weapon was priced at $15.43.

The last 2,000 Savage U.S. M1928A1 Thompsons were manufactured in September of 1942. Thereafter Savage only manufactured the M1 and M1A1 models. Savage manufactured an estimated total of 746,932 model 1928 and M1928A1 Thompsons from April 1940, until October of 1942.

This article is condensed from the book The Military Thompson Submachine Gun, available from Moose Lake Publishing LLC. 207-683-2959 http://www.smallarmsreview.com

Auto-Ordnance, Bridgeport

Although all Thompson Submachine Guns have the Auto-Ordnance Corporation name roll-marked on the receiver’s right side, only a small portion of the total production were actually manufactured at the Auto-Ordnance Corporation’s own Bridgeport factory, especially when compared to the total number made. The Auto-Ordnance Corporation had first relied on Colt’s Patent Firearms Manufacturing Company in 1921, and then Savage Arms in 1940 to actually manufacture the Thompson for them. It wasn’t until the autumn of 1941 that Auto-Ordnance opened its own factory, to assist Savage with the overwhelming wartime demand for the weapon.

Russell Maguire opened his Auto-Ordnance factory in a former automotive brake shoe plant located in Bridgeport, Connecticut. The first months after the building was occupied were spent renovating the facilities, and making tools and gauges not already supplied by Savage. By August of 1941, the plant was manufacturing the U.S. M1928A1 model. At first Auto-Ordnance only made receivers and frames in house. Their guns were assembled with parts purchased from Savage and other subcontractors. The plant ran seven days a week and worked two eleven-hour shifts per day. In January of 1942, Auto-Ordnance began to renovate other buildings on the property to further increase production. The Thompsons being produced in Bridgeport were identical mechanically and in appearance to those being made by Savage. All 1928 Thompsons that were made at the Bridgeport factory had with the letters “A.O.” preceding the weapon’s serial number. The serial numbers, like on the Savage and Colt guns, were roll-marked on the center of the left side of the receiver. A duplicate serial number was stamped on the trigger frames, under the stock slide attachment. The marking of the serial numbers on many Auto-Ordnance, Bridgeport guns was rather carelessly done, as the numbers are quite often unevenly spaced and out of line.

The production of Auto-Ordnance, Bridgeport M1928A1 models began approximately sixteen months after Savage. This would mean that a low serial number Auto-Ordnance, Bridgeport M1928A1 would have been manufactured at the same time period as a mid-range Savage M1928A1, and so on. The receiver markings on Auto-Ordnance, Bridgeport Thompsons differ slightly from those on the Savage guns. All 1928 Thompsons manufactured at the Bridgeport factory were US Model 1928 A1’s. The U.S. designation, like early Savage Thompsons had no periods after the letters.

The receivers of Savage Thompsons were roll-marked on the left side “Model of 1928”, while the receivers manufactured by Auto-Ordnance, Bridgeport were marked “Model 1928” without the word “of “ being included. Another detail difference on the receivers was the abbreviation for the word number, stamped before the weapon’s serial number. On Savage Thompsons the abbreviation “NO.” was used, while Auto-Ordnance, Bridgeport guns used the slightly different “No.” abbreviation. The style (font) of the lettering used on the Savage produced Thompsons was also slightly different than that of the Auto-Ordnance guns.

The Auto-Ordnance, Bridgeport plant was under the jurisdiction of the Springfield Ordnance District. Thompson Guns were inspected and proofed by on site Springfield ordnance inspectors. The Army Inspectors of Ordnance or AIOs of the Springfield District during WWII were Colonel Waldemar Broberg and Lt. Colonel Guy H. Drewery. Colonel Waldemar Broberg using the stamp WB, served as AIO of the Springfield District from 1 July 1941 until 30 June 1942. The stamp bearing his initials has been observed impressed on the receiver’s left side above the magazine well area. GHD was the stamp of Lt. Colonel Guy H. Drewery who replaced Colonel Broberg, serving as AIO from 1 July 1942, until 15 July 1945. His stamp was often placed on the receiver’s left side, just forward of the Thompson Submachine Gun logo. The WB inspector’s stamp would be the most common mark encountered on Auto-Ordnance, Bridgeport manufactured US 1928 A1 Thompsons. Colonel Drewery took the position of AIO near the end of the US 1928 A1 model production run at Auto-Ordnance. His initials are primarily only seen on Auto-Ordnance, Bridgeport manufacture M1 and M1A1 models.

An interesting variation of the Auto-Ordnance, Bridgeport produced US 1928 A1 model that has been observed, are those Thompsons that have had the US designation ground off and the numeral “1” of the A1 mark overstamped with a letter “C” to read AC. A letter X was often added as a suffix on the serial numbers of these guns. Interestingly, some of the AO “1928AC” overstamped Thompsons did not have Army Inspector of Ordnance (AIO) acceptance stamps on them, but were stamped with the Ordnance “crossed cannon” acceptance mark. While other examples of these guns had no government acceptance stamps at all, suggesting that they were never inspected or accepted by the U.S. Government. Perhaps these guns were contract overruns or assembled from parts that remained after the government contracts were filled. However, no documentation could be located that could prove or disprove this theory. The Numrich Arms Corporation also removed U.S. markings from original 1928 and 1928A1 model Thompsons they sold in the 1950’s.

The quality, fit and finish of the Auto-Ordnance produced guns was identical to those of Savage manufacture. Interchangeability of parts was 100% as per Ordnance Department directives.

The West Hurley 1928 Model

The Numrich Arms Company of New York purchased the remaining assets of the Auto-Ordnance Corporation in the 1950’s. They were the third company to do so since 1945. Included in the sale were several complete Thompson submachine guns, and a large number of spare parts. Numrich sold many Thompsons that they had assembled from the parts. Many of these guns have NAC added to the serial numbers. These guns were sold to police departments and a few affluent individuals that could afford the $200.00 transfer tax back in the 1950’s. Approximately ten to twelve guns were sold per year until early 1961 when Numrich ran out of critical receivers and frames and no more Thompsons could be assembled.

In 1975 the Numrich Arms Corporation of West Hurley, New York after receiving approval from the BATF, decided to begin manufacture of both semi-automatic-only and full-automatic versions of the Thompson 1928 model, using the Auto-Ordnance name. The receivers, trigger frames bolts and barrels were of new manufacture, while the remainder of the parts used to assemble the early guns were GI surplus. The parts were Savage manufacture, the original Auto-Ordnance, or one of their subcontractors. As production of the West Hurley guns continued, many parts became unavailable, thus forcing the company to manufacture whatever parts they needed to continue production. In the first year of production there were only 199 select-fire 1928 models made.

In addition to the Thompsons the company also produced a thirty-nine round and a fifty round “L” type drum magazines for the guns. Surplus twenty and thirty round GI magazines were also offered. In 1991 the company began a limited run of the coveted one hundred round “C” drum. There were also special commemorative versions of the 1928 Thompson made. Some of the commemorative West Hurley guns were accepted by the BATF for inclusion on their Curio and Relics firearm list.

Most of the 1928 Thompsons manufactured by the modern Auto-Ordnance Corporation of West Hurley, New York were fitted with a compensator equipped finned barrel, vertical foregrip and a replica of the original Lyman adjustable rear sight. The receivers, frames and barrels of the guns were finished with a black oxide, much like the originals had been. Although the majority of the guns had the aforementioned features, special requests were often honored for specially equipped and serial numbered guns. Special order 1928 guns have been documented with and without compensators, rudimentary military “L” and protected “L” style rear sights, as well as military horizontal foregrips. Wide ranges of custom serial numbers were also issued upon a customer’s request. By the time production ceased in 1986 West Hurley Auto-Ordnance had produced a total of 3,306 select-fire 1928 models. Small production runs of a .22 caliber version of the full-automatic 1928 model were also manufactured.

The West Hurley manufactured Model 1928 receivers were uniquely roll-marked as; U.S. MODEL 1928, with the U.S. mark, but lacking the A1 suffix as stamped on the original military guns. The rear of the receiver’s left side was marked THOMPSON SUBMACHINE GUN CALIBER .45M1. This marking was different than the original markings, and the word caliber was not spelled as calibre as the original 1928’s had been. The center of receiver’s right side was marked AUTO-ORDNANCE CORPORATION WEST HURLEY, NEW YORK, U.S.A. The markings on the trigger frame were reminiscent of those of the WWII Auto-Ordnance guns with the words FULL AUTO on one line. The rocker pivot position arrow was also the smaller design of the original Auto-Ordnance frames.