The Thompson Submachine Gun ID Guide, Part X: The Thompson Drums of West Hurley, Auto-Ordnance

By Frank Iannamico

My previous Thompson-related article focused on the drum-type magazines manufactured during World War II for U.S. and British forces. This article is directed at identifying the Thompson drum magazines that were made by the “modern” Auto-Ordnance of West Hurley, New York in a timeframe that ran from 1975 to 1994.

The impetus of writing this piece was to give collectors and shooters a guide to the markings and variations of these “late manufacture” drums. As with the West Hurley Thompson Submachine Guns, manufactured from 1975 to 1986, there seems to be a LOT of confusion out there regarding these drums. These drums are sometimes mistakenly sold as original World War II types or even of earlier manufacture. Often it is due to an uninformed buyer, seller or both. The use of the “Auto-Ordnance” name is generally the source of the confusion. Hopefully this article will serve to enlighten both buyers and sellers alike.

The original drum-type magazine was offered as an option for the Colt Thompson Submachine Guns, first marketed in the early 1920’s. Oscar Payne designed both the “L” drum and the “C” drums while employed as a designer by the Auto-Ordnance Corporation. The drums from the 1920 era will have a New York address on their body’s slide plate. The Colts Patent Fire Arms Manufacturing Company and Worcester Pressed Steel manufactured the first drums, but both were Auto-Ordnance Corporation marked. There were also several similar Auto-Ordnance marked drums manufactured during World War II. One had a New York address, the other a Bridgeport, Connecticut address. Both of the drums were manufactured by the United Specialties Company under contract with Auto-Ordnance, and these 1940 era drums can be usually be easily identified by a letter U stamped on the cover and body slide plates.

In addition to the Auto-Ordnance marked drums, there were a substantial number of 50-round “L” drum-type magazines manufactured by several military contractors during World War II. The drums were contracted directly with the companies, without any involvement of the Auto-Ordnance Corporation. The drum contractors were; The Seymour Products Company, The Crosby Company and Worcester Pressed Steel. These drums were marked with the actual names of the companies that manufactured them.

Auto-Ordnance, West Hurley Thompson Drums

The 39 Round “XL” Drum

In 1975, the Numrich Arms Company of West Hurley, New York began to manufacture their first Model of 1928 .45 caliber Thompson Submachine Guns for the civilian market. They immediately realized that most purchasers of their Thompsons also wanted a classic drum-style magazine to use or display with their guns. To satisfy the needs of their customers they offered a facsimile of the 50-round “L” drum, but the early West Hurley drum only had a 39-round capacity. The drum was reportedly made by altering a drum that was originally designed for a Japanese manufactured blank-firing replica Thompson. The 39-round drum was called the “XL” drum and retailed for $44.50 in 1975. The West Hurley 39-round drum is easily identified due to its lack of markings on the slide plates, and the markings “AUTO-ORDNANCE CORPORATION WEST HURLEY, NEW YORK, U.S.A.” that were placed on the magazine’s cover just under the winding key. While the outside dimensions were similar to an original “L” drum, the internal track and rotor design was quite different from the original manufacture 50-round drum. In 1980 the price of the “XL” drum was increased to $64.95, and production of the “XL” drum was discontinued around 1987.

The 50 Round “L” Drum

While the 39-round drum satisfied some Thompson owners, there was a desire by many others to have a more authentic, full capacity 50-round “L” drum. In response, the West Hurley Auto-Ordnance Company introduced their .45- caliber 50-round Thompson drum magazine in 1988. Reportedly the original blueprints and tooling were used to produce them. This particular drum is the one that has caused much confusion among enthusiasts. The markings on the West Hurley 50 round drum closely emulated those of an original 1920’s era New York address drum, and is often mistaken as an original early manufacture drum. The rotor and track assembly was also designed like the originals. Unlike the earlier 39-round drum there are no West Hurley markings on the 50-round drums made by the company. When first introduced the retail price of the West Hurley 50-round drum was $139.00 or if you wished to buy a pair of the drums, the price was reduced to $109.00 each.

The West Hurley drum cover slide plate markings:



The West Hurley drum’s slide plate markings riveted to the cover give the winding instructions.

On the drum’s cover the winding instructions are repeated and the Thompson “bullet” logo is present.

(Some Bridgeport and NY address drums will have the winding instructions on the cover, but original New York address drums do not have the Thompson “bullet” logo stamped on them)

Note that original manufacture New York address drums have different markings on the drum body slide plate. The original markings include the state abbreviation, N.Y. and U.S.A. after New York. Also note there are two patent dates rather than the phrase Registered in the U.S. Patent Office

NOTE: only one of several variations of the original NY drum markings is depicted here.

A typical example of original New York address drum markings on the body slide plate;

NEW YORK, N. Y. U. S. A.
JULY 27, 1920 DEC. 7, 1920

Typical original New York address drum markings on the cover slide plate:


The 100 Round “C” Drum

Original manufacture 100-round Thompson “C” drums are quite rare and highly sought after by serious collectors. Along with being rare, the original “C” drums, when located, can be very expensive, costing thousands of dollars. The Thompson “C” drums were manufactured beginning in 1921; the original retail price was $20.00. In 1990 when Auto-Ordnance of West Hurley, New York announced that they were going to be manufacturing a replica of the coveted 100-round Thompson “C” drums, collectors and shooters lined up to buy them. The West Hurley “C” drums were priced at $345.00 each, retail, or if you wanted to buy two of them you could get them for $275.00 each.

Unfortunately as it turned out, the West Hurley “C” drums generally did not always function as intended. While most of them worked fine in the semiautomatic mode of fire, attempting full-auto fire usually resulted in stoppages after firing only a few rounds. One of the problems was that the rotor drive spring could not keep pace with a full-auto Thompson’s high rate of fire. There were other concerns with fit and overall quality of the unit as well. After becoming aware of the feeding problems, the factory reportedly redesigned the rotor drive spring in 1991. In 1992 the retail price of the “C” drum was reduced to $225.00.

At first glance the West Hurley “C” drums appear quite similar to an original. However, due to the rarity of the original “C” drums, there are many potential buyers out there that have never had the opportunity to closely examine one. The following text will describe the differences between an original “C” drum and one of more recent manufacture.

Original 1920’s Colt production “C” drums are marked and serial numbered on the slide plates. The original slide plates are flat, there are no vertical ribs stamped into the plates. There are no markings on the drum’s cover or body, the only markings on the drums are on the slide plates that are riveted to the body and cover at the 12 o’clock position. Original drums have a nickel-plated rotor that is dull silver in color. The rotor can be viewed by removing the cover from the drum. The rotor shaft that holds the winding key is also nickel-plated and is hollow.

The West Hurley A-O “C” drums are also serial numbered, but the lower numbers (under 1000) begin with a zero. There are winding instructions, “WIND TO 15 CLICKS” and the Thompson “bullet” logo roll marked on the drum’s cover. The rotors are blued. The shaft for the winding key is solid. The slide plate rivets are different sizes, and the sheet metal slide plates both have vertical ribs stamped into them. Lastly, the mounting rails that are formed on the slide plates are rounded rather than square.

The “X” Drum

On September 13, 1994 the Violent Crime Control and Law Enforcement Act of 1994 (Public Law 103-322) was enacted into law. This new law effectively banned the further manufacture of any firearm magazine with over a 10-round capacity. This of course included the 50- and 100-round Thompson drums that were being produced at the time. After the change in the law, the West Hurley A-O introduced the .45 caliber 10-round capacity drum designated as the “X” drum, “X” being the Roman numeral for 10. The “X” drum is the same size and dimensions as the earlier “L” drum, but of course its capacity, in order to comply with the 1994 law, was reduced to only 10 rounds. The retail price of the “X” drum was $89.95 and although functional, the drum was primarily intended for use as a display piece. Thompson “X” drums are still offered by the current Auto-Ordnance, currently operated by Kahr Arms. They also reportedly still offer a large capacity “Law Enforcement Only” 50-round “L” drum.

.22 Caliber Thompson Drums

In 1980 West Hurley A-O offered a .22-caliber conversion kit for the .45-caliber Thompson. Along with the conversion kit they introduced a 108-round capacity .22-caliber drum magazine. The retail price of the magazine was $89.75. In 1981-1982 the 108-round drum was discontinued and a new 10-round .22-caliber drum was introduced. The new drum body incorporated a magazine from a Harrington and Richardson .22-caliber rifle to feed the rounds. In 1985, the 10-round .22-caliber drum was discontinued and a 50-round .22 caliber drum introduced. The latest drum was made by merging a drum from Mitchell Arms PPSh41 .22-caliber replica rifle, and the back of a Thompson box magazine. The price of this drum was $79.95.

The full-auto .22-caliber conversion kit was discontinued in 1985. A limited number of select-fire .22-caliber Thompson Submachine Guns were also produced in the 1980’s along with a .22-caliber semiautomatic-only version.

Today, the original Thompson “L” and “C” drums continue to spiral upward in price at a phenomenal rate. Climbing right along with them are West Hurley A-O’s “modern” manufacture “L” and “C” drums.

Special Thanks to the following gentlemen for providing technical assistance, and/or photographs used in the preparation of this article.

Sutton Coffman
Sid Crandall
Mike Hensley
Tracie Hill

This article first appeared in Small Arms Review V6N8 (May 2003)
and was posted online on November 22, 2013


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