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Thompson FAQ: Check Here First

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This page became corrupted when I attempted to update it on 3/30/19 - I am currently in the process of recovering it.


If you would like to contribute, please send an e-mail message to David Albert at dalbert@sturmgewehr.com.


Many thanks are due to the originator of the FAQ section, The1930sRust, and the section will continue to be updated as necessary going forward. I would also like to thank member "cbmott" for suggested updates that he sent, which were updated to this section on 3/30/19.


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An impressive gathering of Thompsons, including the engraved Colt "Midas" Thompson


Welcome! And thank you for visiting the MachineGunBoards.com Thompson Forum. If you are new to the world of Thompsons and are a first time visitor to the forum, we encourage you read the FAQ listed below. Many of the most common questions concerning Thompsons, both the semi automatic and full automatic varieties, are found here. Then, register as a user! If you have questions or comments not addressed below, please feel free to post them.




What are the different variations of the Thompson, and how much do they cost?

There are five distinct categories of the most commonly encountered Thompson guns:


1. Original production, Colt manufactured submachine guns. 15,000 were manufactured by Colt for Auto-Ordnance, and were commercially available from 1921 to 1939. These include the original Model of 1921 (which in 1926 became the 1921AC with addition of the Cutts compensator), and Model of 1928 Navy (a.k.a. "Overstamp," because the "1" in "1921" was overstamped with an "8"). A semi-automatic version of the 1921, the Model of 1927, was marketed in limited quantities, through modification and re-marking of the Model of 1921. The Colt Model of 1921 Thompson value is approximately $32,000 and up as of March 2019 depending on condition and number of original Colt manufactured parts included with the gun. Thompson Model of 1921, 1928, and M1


2. WWII production models. The most prolific, these Thompson's include the Model of 1928A1 (which can be further divided into several variants), the M1, and M1A1. These Thompsons were produced by either Savage or Auto Ordnance from 1940 to 1944. The Model of 1928A1 Savage or Auto Ordnance Thompson may bring $20,000 and up. M1 and M1A1 versions slightly less, at approximately $23,000 and up. M1 and M1A1 versions slightly less, at approximately $21,000 and up.


3. NAC Thompsons. These are Thompsons legally manufactured (assembled) under the NFA and marketed by Numrich Arms during the 1950's and 1960's. They are stamped with either a "NAC" prefix or suffix in relation to the serial number. Many of these Thompsons were assembled from parts when Numrich acquired the Thompson, and its remaining spare parts, fixtures, and manufacturing equipment from making the TSMG at Colt, Savage, and AO Bridgeport manufacturing facilities.


4. Modern production models. These include the .45 caliber Model of 1928 Thompson manufactured in West Hurley, NY, from about 1972 until 1986 (although some law enforcement only models were produced in 1992). A model of the M1 (though technically an M1A1) was also produced from 1985-86. These guns were virtually identical to the WWII guns. Some of these full auto West Hurley Thompson's were also chambered in .22 caliber. Also, several "commemorative" full auto models were also produced. Many characterize these guns as "shooters", though they have become collector firearms in their own right. West Hurley Thompson's, though the least expensive full auto guns, still range in price from $15,000 to as high as $20,000.


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West Hurley 1928 owned by R. Lish, metal by P. Krogh/Diamond K and wood by Dan Block


5. New production models. Kahr Arms currently produce ten different versions of the venerable Thompson gun. These include six semi-automatic carbines (patterned after the Model of 1928 and the M1). These carbines are available in either 16 1/2" barrels (non NFA) or 10.5" barrels (which are considered Short Barreled Rifles, and require a Federal stamp to own). These carbine receivers cannot be modified to fire full auto. The 1927 models will also accept drum magazines. The carbines retail for approximately $800. Kahr also produces (late 2003) new production models of the 1928 and M1 submachine gun, but these weapons can only be exported or purchased by law enforcement agencies. Kahr also offers (2004) non-firing display versions of both the Model of 1928 and M-1. *All prices are approximate in 2008 USD.


Are West Hurley submachine guns real Thompsons?

This is a subject of some debate among Thompson collectors. Purists argue that, no, they are not. Citing the somewhat blurry history of the Auto-Ordnance Company, its purported cessation of operation 1944 (and its numerous subsequent changing of hands), some believe no new Thompsons were produced after the end of WWII. Others contend that the guns produced by Numrich Arms Company, first of Mamaroneck, New York, later of West Hurley, New York in the 1950's and 1960's, as well as the Auto Ordnance Company of West Hurley, NY, in the 1970's and 1980's, are the direct descendants of the original Thompson. At one time there was evidence to support both ideas. However, it has now been established the succession of the Thompson gun extends from 1916 to the present ownership by Kahr Arms. While the modern production West Hurley guns do not possess the unique history of the original Thompson (they were not carried by gangsters, bought by police departments of the depression era, or carried into battle by soldiers around the world) they nonetheless possess the aura of the "gun that made the twenties roar" and are historically significant in and of themselves: they are the last of their kind.


West Hurley 1928 (with 1921 actuator) 100 round drum dump (Insert link)


I see Thompson drums listed as "L" or "C". What does that mean?

The two most commonly encountered types of Thompson drums are designated as the "L", for the Roman numeral for 50, and "C", for the Roman numeral for 100. These, then, denote the drum capacity. You may also see "X" drums, 10 round capacity, and 39 round drums. The latter are not very popular, but the 10 round drums were produced during the assault weapons ban to conform with magazine restrictions. New production "L" drums and "C" drums are available from Kahr Arms, and some newly manufactured Taiwanese "L" and "C" drums are also available. Original production "L" and "C" drums can still be legally purchased in most states, but cost between $400 and $7000 depending on the make and capacity.


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Thompson L Drums and GI ammo


How many rounds do Thompson's hold?

Drum magazines will hold 10-39-50 & 100 rounds. Stick magazines or Box magazines will hold either 20 rounds or 30 rounds.


How do I load a drum magazine?

Just click on Drum Feeding Instructions for step by step....steps.


Will the M1 and M1A1 Thompson accept a drum magazine?

NO. The were not designed to do so.


I have heard Thompson drum magazines need to be greased from time to time. Is this true??

Yes. Drum greasing is recommended, but is a maintenance task that will not be necessary very often. The Chinese "Crosby" drums are coming in without grease, so if you bought one from Numrich recently, or in the original batch of 200, you should make sure you grease it before use.


Where can I buy spare parts for my Thompson?

As of 2003, there are several places you can find NOS (new old stock) and new production Thompson parts:


The Tommygun Homepage

Numrich Arms/ Gunparts Corp

Sarco, Inc.

Sportsmans Guide

International Military Antiques

Wolff GunSprings

What A Country magazines

Northridge International



SRT Arms (1928 buffers)


Also, quality parts can be obtained from: Phil at philfordpartsNOSPAM@yahoo.com **Remove NO SPAM and

Doug Richardson ('Offers You Can't Afford To Refuse' catalog request: $5 to 2100 McReynolds Road, Malibu, CA 90265; 310-457-6400 10am-11pm)


Is there a reputable, competent, Thompson gunsmith I can send my semi or full auto Tommy to for work, modifications, or tweaking?

Diamond K/Paul Krogh p-k@[NO SPAM]q.com **Remove NO SPAM 1390 East 7th Street Delta, CO 81416 970-874-5750 ---------------------- Paul (the boards 'PK') performs quality repairs and modifications on all Thompson full automatic and semi automatic guns. Specialities include, but are not limited to, West Hurley tweaking, semi automatic modifications, short barrel replacements, sight and compensator pinning, polishing, reblueing, L drum work, and general gunsmithing chores. Paul also offers specialty modifications including enhanced '28 pilots, '21/ '28 hybrid pilots, modified '28 to '21 actuators, '28 Polyurethane buffers, and '21 style ejector conversions. Custom 1921 SA Thompson owned by Devlin B. Powers, work by P. Krogh Who will work on my Thompson drum magazine? Diamond K/Paul Krogh p-k@[NO SPAM]q.com **Remove NO SPAM 1390 East 7th Street Delta, CO 81416 970-874-5750 --------------------- Paul can reblue all magazines and drums, and can tweak West Hurley magazine to fire, and can also work on 20 and 30 round stick mags.


Where can I find complete guns?

Here is a list of several popular websites to purchase complete NFA firearms:






Does anyone make replacement stocks for the Thompson?

Dan Block hand makes exquisite replacement walnut woods for all Thompson models. Dan is "Deerslayer" on this board, and can be reached using the internal e-mail system. Feel free to also visit his website at http://www.thompsonstocks.com/


Does anyone make high quality reproductions of Thompson hard cases, specifically for the fully automatic guns?

Greg Fox manufactures handcrafted FBI, Police and Indiana hard cases for the Thompson SMG models 1921, 1928 and 1928A1. He also makes a custom hardcase for the M1 Thompson. Contact Greg at M1921A"NOSPAM"@AOL for details and prices.


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Custom M1 Thompson case by Greg Fox


Mark Layton also makes 2 types of custom Thompson chests: http://www.thompsoncases.com


What about wood refinishing? There are many ways to refinish Thompson wood. First of all, however, some advice: if the wood is original, make sure you really want to do this! If your wood is grimey, Cosmoline or grease covered, you need to strip all this off. Easy~Off spray on oven cleaner will do this. Liberally spray the wood and let it stand for 15 minutes or so. Be careful, this stuff is basically foamed lye. Caustic and odorous too. After this, the wood must be washed. A very hot water bath will work. Some people also use Murphy's Oil soap, or an SOS pad to get even more dirt and grime off. The wood can be bleached, but the result is quite often a bone white piece of wood! Some dents in the wood can be raised by placing a wet cloth over them and using an iron on the depression. The bath process will raise the grain of the wood significantly. After the wood is allowed to completely dry, it must be sanded. A great way to do this is to wet sand it. Make a sanding "block" out of a piece of thick felt or other soft pliable material, and wrap it in varying grades of sand paper. This will allow the paper to conform to the surface of the wood, and eliminate the possibility of flat spots. Now, soak the sand paper and felt sanding block in denatured alcohol and sand away! You can start with a coarse grade paper and move up to the really fine grit. Be sure to keep the block wet. Of course, you can dry sand the wood, too. Once the wood is sanded and allowed to dry, staining can begin. There are many schools of thought here, and ways to do this. Some choose just plain boiled linseed oil or tung oil. Depending on how light your wood was to start with, the wood may turn out too light with just an application of these oils. A good stain that leaves a rich chocolate color, similar to the look of a piece of military wood, is Jacobean stain. Others prefer Walnut. Once the color is achieved, linseed oil or tung oil can be added as a last step (again, after the stain has dried) and hand rubbed. One option, before a final oil coat is added, is to try a military dye, such as Vanderhaves Formula XIII. It will impart a light brown color with red overtone. This is a personal choice. Addition of military dye over stain If your pieces of wood don't end up matching (they seldom do) you'll have to experiment with multiple coats. Sometimes, a light steel wool application on the lighter pieces may help them to take the stain better. Linseed oil is a fine maintenance coat that can be applied over your finished product occasionally. Also, one can make a paste of equal parts linseed oil, bees wax, and turpentine (heated over a hot plate and allowed to congeal) that can be hand rubbed in to the wood occasionally. Again, these are merely suggestions of one way to proceed with refinishing.


I bought a sling for my Thompson. How do I install it properly?

See The Rifle Sling Homepage for detailed instructions.



What do all the abbreviations I see here mean?

Some of the more common are listed below:

AO= Auto Ordnance Corporation (or AOC)

BATF(E) or ATF= Bureau of Alcohol, Tobacco and Firearms (and Explosives)

BBL= barrel

C&R= Curio and Relic

DS = Dealer Sample machine gun classification under the NFA of 1934

FA= Full automatic

GBTTGS = "Great Britain - The Tommy Gun Story," book by Tom Davis, Jr., 2014

JTT= John Taliafero Thompson

NAC= Numrich Arms Corporation

NFA= National Firearms Act of 1934

NOS= New Old Stock

RKI= Reasonably Knowledgeable Individual

SA= Semi Automatic

SBR= Short Barrel Rifle

TATA= The American Thompson Association

TCA= Thompson Collectors Association

TG= (2 Meanings:) 1. "Thompson Gun" 2. "Thompson Greed" (The latter originated from Ron Kovar, referring to outrageously escalating prices in the Thompson collector world)

TGTMTTR= "The Gun That Made The Twenties Roar," book by William J. Helmer, 1969

TSMG= Thompson Submachine Gun, or sometimes Thompson SMG

TUTB= "The Ultimate Thompson Book," book by Tracie L. Hill, 2009

WTB= Want To Buy

WTK= Want To Know

WTS= Want To Sell

WTT= Want To Trade




What does the "sub" in submachine gun mean?

The term "submachine gun" was first used to describe the Thompson. The term "sub" means they use pistol caliber ammunition rather than rifle caliber ammunition (which would make it a full "machine gun").


Can I own a fully automatic Thompson?

Probably. Most states (34 of them) will allow ownership of a submachine gun.


How do I know if my State will allow Machinegun and other NFA ownership?

See http://class3laws.com/


What's the dope on getting approved for a transfer?

First, find a gun. Then obtain and complete the proper BATF paperwork (generally a 'Form 4'). You must also be finger printed. This paperwork, then, is submitted to the BATF, along with $200. The process takes approximately 7 months.


Even if I could afford one, I'd hate having to pay $200 a year to keep it!

The $200 federal tax associated with most Thompson guns is only paid once per transfer.


Is there a link that shows which NFA examiner is working on my transfer?

Yes. https://www.nfatracker.com/


Is there a way to track how long my transfer paperwork will take?

Yes, this website tracks when all applications were submitted and when they were approved. https://www.nfatracker.com/


Can a demilled Thompson be legally be brought back to life with the proper BATF approval?

In short, NO! Any machinegun manufactured after 19 May 1986 is considered a post sample machinegun. These are available only to police departments, Class 3 dealers, Class 2 manufacturers, and Class 1 importers. In order to remanufacture a post sample machinegun you must get a Type 07 Federal Firearms License, pay $500 to the BATFE for your Class 2 Manufacturers Special Occupational Tax (SOT), then register with the US State Department for an additional large sum of money. This will get you in the door. If you choose to do all of this, then you can remanufacture a Thompson. After you have done that, you can only keep the weapon as long as you pay these YEARLY fees!


OK, then. Can I make a dummy display gun by rewelding demilled receiver pieces back together?

No, this could be interpreted by the BATFE as trying to construct an unserviceable machinegun. Several variations exits, where persons reweld the front and back receiver pieces to a solid core, or even having the back half of a severed bolt free to move. All these designs are illegal and can result in serious legal problems. For display guns, it is recommended that you use solid dummy receivers, commercially available. "Reconbob" on this board manufactures 80% complete Thompson display receivers of excellent quality as well as blank firing only models. Here is a link to his website: http://www.philaord.com/


I'd like to buy a fully automatic Thompson, but about all I can afford is a West Hurley. I've heard they sometimes have problems. What's the deal?

The Thompson submachine gun as manufactured by Auto Ordnance in West Hurley, New York, is a true Thompson in every way; all parts are fully interchangeable with guns made in previous dispensations. Unfortunately, the care exhibited in the manufacture of the earlier guns was not apparent in these later examples. They can, however, be as reliable and satisfying if proper steps are taken to ensure such. While many surplus GI parts were used in the assembly of these guns, some of the more difficult to obtain and expensive surplus parts were reproduced of lower quality materials and processes, and should be replaced with original GI surplus. Most notable of these is the actuator. Others include the trip, paddle style control levers, magazine catch, barrel and rear sight. All of these latter parts can be serviceable, however the West Hurley buffer pilots should be replaced in any event. The receiver is made from a steel alloy of lower strength. It is not "pot metal" or "soft as butter," just not up the hardness standards of the early guns. West Hurley guns have been known to have digested several hundred thousand rounds and still be serviceable. One of the potential major problem areas is in the machining of the receiver. Unfortunately, tight tolerances were not adhered to in their manufacture, but in almost every case this can be corrected by a competent and experienced "thompsonsmith" and once done, the receiver should be entirely compatible with all TSMG parts and function as well as any "Tommy" is expected to. This is a one time expense (which could run as high as $4000) and should be figured into the price consideration of any gun that has not been so treated. The West Hurley Thompson is the last of the breed and if properly inspected and brought into standard will provide a lifetime of enjoyment and satisfaction to its owner.


Ok. But is there any truth to the West Hurley 1928's having receiver problems, like cracking from fatigue?

There was a time when some individuals promoted speed bolts, and cutting the ears off the Blish locks to supposedly enhance reliability and increase cyclic rate. Guns so modified may be destined for trouble; they are way outside their original design parameters. Cracked receivers likely involved these modifications and/or hot handloads. While the West Hurley receivers are softer than the Savage, Bridgeport or Colt guns, this actually makes them less likely to crack under normal use (soft metal gives, hard metal is more prone to break). They will wear out faster, but not in your lifetime. If you get a West Hurley that has not been "blue printed" (checked against original specifications and adjusted by a gunsmith), expect to pay some extra to get it set up correctly. Once this is done, it will be a good shooter.


I have a West Hurley Thompson. Is any information available about their serial numbers and production dates?

Yes, West Hurley Thompson serial numbers can be researched at the link below:



What are the basic steps for disassembly of my full auto Thompson Model of 1928?

First, remove all magazines or drums and make sure the weapon is unloaded. Retract the actuator/bolt and visibly inspect the chamber (stick your finger in there) and be sure no live rounds are present. Check again. Set the selector to "auto" and the safety to "fire". Now, close the bolt by pulling the trigger and retarding the forward movement of the actuator/bolt with your hand; don't let it slam home. Turn the gun over and locate the frame latch (the button at the rear of the trigger housing). While depressing it with the right thumb, lightly tap the rear grip with the palm of your left hand, striking it towards the rear of the receiver. The trigger assembly will slide back. Slide it rearward and pull the trigger to remove. This will give you access to the bolt/spring/pilot in the receiver, as well as the individual parts of the trigger assembly. To remove the pilot and spring, you must reach in with two fingers and lever out the pilot and buffer away from the rear of the receiver. Be careful, as it will be under spring tension. Once the pilot shaft has cleared the receiver hole, pull it out and remove it and the main spring. The bolt will then lift out, along with the actuator and Blish lock. Consult a detailed guide for further take down procedures, such as the CD on the Colt and military M1 and 1928A1 Thompson Submachine Guns. Reassemble in reverse order. Place the spring over the pilot and push it down as far as it will go by hand. Then place a paper clip or other piece of thin metal through the hole in the end of the pilot (make sure the flat place on the pilot flange is facing away from you) to trap the spring. This process makes it easier to insert the free end of the spring in the bolt/actuator and lever the end of the pilot back into the receiver hole. Once this is accomplished, pull out the paper clip/metal and the spring will rebound. Finally reinstall the trigger housing.


Are there videos online that show disassembly so I don’t have to buy a CD/DVD?

Yes, a search of “Thompson Submachine Gun” will yield several good disassembly videos on youtube.com as well as an old army training film on the “principles of operation” of the 1928A1 Thompson.


What is the Rate of Fire (ROF) of the Thompson?

1921 model- 800-900 rounds per minute; 1928 models 600-700 rpm; M1 & M1A1 700-800 rpm.


How many fully automatic Thompson guns did Colt manufacture?

15,000 were officially manufactured with serial numbers 41 thru 15040.


How come, when I pull my Thompson actuator back, it seems to "cock" in two positions?

There are two notches in either the 21/28 or M1/A1 bolts (towards the front of the rectangular body) which will hold the bolt in the cocked position, one a little further back than the other. The first notch catches the bolt in the rear most position. The second notch is about 5/8" back of the first and will allow the bolt to be that much further forward when cocked. Its purpose is to catch the sear if the first notch misses it in semi auto fire. The third notch in the M1/A1 bolt (towards the rear of the bolt) allows the sear to raise up so the safety can be engaged with the bolt closed.


How many Thompson's were made for WWII?

Savage & Auto-Ordnance made approximately 562,511 Model of 1928's, about 285,480 M1's, and 539,143 M1A1's, give or take a few.


Who made parts for WWII Thompsons? Is there a way to tell by their markings?

Most partswere made by 3 companies, Auto Ordnance, Savage Arms and Stevens Arms. Parts made by Auto Ordnance were marked “AOC”, while Savage marked their parts with an “S” and Stevens marked their parts with a square off S that gets mistaken for a “5”. The book American Thunder III by Frank Innamico is a great resource for more information. There has also been much discussion on this board of the less frequently encountered manufacturers.


I found a few full auto Thompsons for sale, but they are listed as 'Pre May' and 'PRE-86 Dealer Sample'. Why are they so cheap? What gives?

Pre 1986 and post 1986 dealer sample Thompsons can only be owned and transferred between Class 3 gun dealers. Consequently there is little market for them, and hence a lower price. And, no, you cannot simply become a dealer to own them!


Do automatic Thompson's climb? Not really, I've left mine at the bottom of the stairs and it never moved up. But if you leave them laying around one may walk off...Seriously, though, Thompsons are extremely controllable when utilizing the correct stance. Those who claim they are uncontrollable know very little about them, or their proper use.


What carrier should I use if I need to ship my full auto Thompson? (All NFA Rules Apply)

The following summary is courtesy of "Roscoe Turner" on the board, and is information we should all familiarize ourselves with should the need arise to ship our Thompson, or other NFA item to a gunsmith. (Please take special note that All NFA Rules Apply when shipping an NFA item.)


Shipping of NFA firearms:


UPS: Shipping NFA such as a machine gun via UPS is pretty cut and dry according to their tariff - "UPS does not accept automatic weapons, including machine guns, for shipment." http://www.ups.com/c...s/firearms.html Not much room for discussion with those folks. If you ship one and it is lost or damaged, you are on your own. UPS will not honor the insurance coverage for your shipment. Bottom line...don't use UPS to ship NFA under any circumstances.


FedEx: Updated 10 Dec 12 FedEx no longer has the restriction on firearms insurance as previously reported, the current level is $50,000. Questions about shipping via FedEx can be answered here under firearms - http://www.fedex.com...ound/index.html


United States Postal Service: Finally and surprisingly is the best service for shipping NFA firearms, the United States Postal Service. Shipping via the USPS is the safest and most cost effective way of shipping NFA items. With Registered Priority Mail your package is signed for each time it changes hands and can be insured to a value of $25,000. In most locations the package will be delivered within 2-3 days. When shipping using the USPS be sure to state at the counter you wish the package to be mailed Registered Priority Mail. If you simply state registered mail the clerk may assume you want it shipped First Class Registered Mail which will limit your options. This was recently brought to my attention when a seller attempted to ship a NFA firearm to me and his local post office could only insure the package for a maximum of $5000. Always declare what is in the box. If your post office is not familiar with the regulations regarding shipment of NFA items, do not take no for an answer - educate them, and escalate to management, if necessary. This process may require multiple calls or visits, and an introductory visit without the package is recommended to ensure subsequent smooth handling of the transaction.




Are the new Kahr Thompsons reliable out of the box?

Not always. Unfortunately, few of them work and continue to work without a gunsmiths touch or being returned to the factory for replacement parts. There are Thompsonsmiths that can repair them so that they fire flawlessly, however.


Can I convert a Semi Auto to a Full Auto?

NO! You cannot do this. Doing this will land you in jail for 10 years. Certain Federal Firearms License Holders can do this, however the guns they make cannot be registered for transfer to an individual. There are special full auto bolts that can be "dropped in" to the semi automatic Thompsons. These bolts are considered registered NFA items themselves and can cost many thousands of dollars.


What is the process for installing a short 10.5" barrel on a semi automatic Thompson?

This is classified as constructing a Short Barrel Rifle or "SBR". SBR's are regulated by the National Firearms Act and require approval by the BATFE. First, you must see if your state allows the SBR. Then, you must apply using form ATF F-1, "Application to Make and Register a Firearm," along with ATF fingerprint cards, and citizenship certification form. Send two originals of each form, along with a check of $200 to National Firearms Act Branch Bureau of Alcohol Tobacco and Firearms. The waiting period is approximately 8 months. You must not possess the short barrel until after you receive your approved application. Installing a barrel on your Thompson can be a tricky and is not as simple as just unscrewing one and installing the new one. It is a job best done by a competent gunsmith. Because you are manufacturing a NFA firearem, you must conspicuously engrave on your receiver your name, city, and state, engraved to a height of 1/16th in. and depth of .003 in. Remember your newly constructed firearm must now comply with all the rules that regulate NFA weapons. You must have approval to transport it out of state, and you should always keep a copy of your stamped Form 1 with the firearm at all times. To obtain forms and learn more about NFA regulations, use the following link: http://www.atf.treas...earms/index.htm ***The above phrase "on your receiver" is not correct in every case. Depending on the particular application, the information may be placed elsewhere.


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Customized Kahr 1927 SA Thompson with short barrel, owned by Grey Crow. Gunsmithing by P. Krogh


When I have a short barrel installed on my semi automatic Thompson, do I need to take it to a class 3 dealer/gunsmith to get it installed, or can I take it to a non class 3 gunsmith?

Any gunsmith with an 01 FFL can accept the gun for service, and you do not have to wait while the work is done; it can be left at the smith.


I understand the semi automatic Thompsons won't accept original G.I. stick magazines. How do I modify the magazine catch to accept G.I. 20 and 30 round sticks?

The magazine catch must be modified by lowering the lip that engages the magazine .100" while maintaining the original contours and shape. This is commonly achieved with a Dremel tool, or files. After you have removed the safety, move the pivot plate so the ends of the pins are flush with the side of the trigger frame. Pivot the magazine catch out far enough to clear the magazine engaging protrusion from the hole in the trigger guard. Push on the end of the pivot pin part of the mag catch on the far side while pulling the catch out of the hole. Once the magazine engaging protrusion has cleared the side of the trigger guard, carefully allow the catch to rotate and unwind the spring. Remove the catch from the trigger housing . (Assemble in reverse.) When reshaping the magazine catch, you must duplicate all the contours and angles when lowering the engaging surface. Removing .100" will allow use of unmodified GI magazines. Be careful not to remove too much metal. You may have to refit and test several times to acheive the optimal shape.


How are the adjustable rear sights on West Hurley and Kahr manufactured Thompsons different than Colt and WWII manufactured Thompsons?

Original, adjustable Lyman sights are marked with the Lyman name, and feature a windage adjustment knob. Colt and WWII era Thompsons, as well as early Numrich/AO West Hurley Thompsons had Lyman sights installed. Most West Hurley and Kahr adjustable rear sights are made from M1917 Rifle sights, which have a ladder/detent adjustment, with bases made of either steel, aluminum, or potmetal. Current Kahr sights have steel bases.


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Lyman Adjustable Rear Sight


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Lyman Adjustable Rear Sight Mounted on West Hurley Model 1928 Thompson


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West Hurley Adjustable Rear Sight Above

Images Courtesy The1930sRust ==============================================




Starting from the top left corner:


The World's Submachine Guns (Machine Pistols), Vol. 1, by Thomas B. Nelson, 1963. International Small Arms Publishers. Out of print. Library of Congress Catalog Card Number 63-14797. 739 pages, with 34 pages on the Thompson. This is the first volume in a 4-volume series on weapons. (Actually, there are 5 volumes, but one is not an official part of the World's Weapons series) My copy is signed by the author in 1967, to the inventor of the Smith and Wesson Model 76 Submachine Gun.


The Gun that Made The Twenties Roar, by William J. Helmer, 1969. MacMillan. (This is a first edition) Out of print. Library of Congress Catalog Card Number 69-12648. 286 pages. Exceptional book written by the author while he was at the University of Texas at Austin. It covers the history of Auto-Ordnance in great detail, written as a master's thesis. Bill Helmer is a good friend of mine, and has written several gangster related books of note that are also recommended to Thompson collectors who might have an interest in gangster history.


The Gun that Made The Twenties Roar, by William J. Helmer, 1969. The Gun Room Press. (This is a second edition printed by the Gun Room Press in 1979 with an additional chapter by the late George C. Nonte, Jr. covering West Hurley Thompsons.) Out of print. ISBN O-88227-007-25. 229+ pages.


The Complete Book of Thompson Patents, by Donald G. Thomas, 1980. Desert Publications. Out of print, and difficult to find. ISBN O-87947-131-X. 493 pages pages. This book simply reprints all Thompson patent paperwork known at the time.


The Thompson Submachine Gun, by Roger A. Cox, 1982. Law Enforcement Ordnance Company. Out of print, and expensive to buy. Prices are currently $250-$350 to acquire this book. No ISBN noted, however there is a 1986 38-page supplement that has ISBN 0-943850-00-3. 231 pages. This was the definitive work before Tracie Hill's American Legend book. It is good, and contains some manuals printed in their entirety, but don't feel like you have to fork out the bucks to acquire this one. Tracie's book has more content, and covers just about everything that this book does.


Notes on Auto-Ordnance, The Thompson Submachine Gun, Second Edition, by James F. Bannan and Tracie L. Hill, 1989. Out of print. South West Publishing Co. No ISBN noted. 307 pages. This book is predominantly pictures of Thompson accessories, and is a good reference piece that I use from time to time. Most items are covered in Tracie's later book.


Les Pistolets Mitrailleurs Thompson, by Jean Huon, 1995. The original is out of print. French book on Thompson Submachine Guns - Text is in French. ISBN 2-9508308-2-X. 128 pages.


Thompson, The American Legend, The First Submachine Gun, by Tracie L. Hill, 1996. Collector Grade Publications. Out of print. ISBN 0-88935-208-9. 559 pages. You must have this book if you like Thompsons.


The Thompson Submachine Gun, Classic Weapons Series, by Chris Ellis, 1998. Out of print. Military Book Club. No ISBN noted. 64 pages. Marginal Thompson book, not necessary to have. Has good WWII pictures, some of which cannot be found printed elsewhere.


American Thunder, The Military Thompson Submachine Guns, by Frank Iannamico, 2000. Out of print. Moose Lake Publishing. No ISBN noted. 294 pages. This is a great book covering military Thompsons better than any other book up until it was published. It has been replaced by even more thorough books, American Thunder II, and American Thunder, Third Edition.


Les Pistolets Mitrailleurs Thompson, by Jean Huon, 2002. This book is still in print. Editions Crepin-LeBlond. Updated French book on Thompson Submachine Guns - Text is in French. ISBN 2-730-0213-0. 135 pages.


Colt Thompson Serial Numbers, by Gordon Herigstad, Volume Four, 2004. Out of print (Retailed for $280 + shipping when last available) Published by the late author. The most recent volume available is Volume 6. No ISBN noted. If you are seriously into Colt Thompsons, then you should acquire this book that attempts to document the history of every one of the 15,000 Colt Thompsons produced. It has history you will not find elsewhere for individual serial numbers. It is a tome of about 1,000,000 pages...(not really, but it's over 3 1/2 inches thick, and leather bound.) Very nice book to have in the library. They are individually serial numbered like Colt Thompsons, beginning at #41. I have #241, which was the 200th book printed.


Submachine Guns of the United States of America, by Frank Iannamico, 2004. Moose Lake Publishing. Currently available at the following website: http://www.machinegunbooks.com This is a great book in general, and has an excellent chapter on West Hurley Thompsons. 486 pages. ISBN 0-9742724-0-X.


American Thunder II, by Frank Iannamico, 2004. Moose Lake Publishing. Out of print. 536 pages.


On The Side of Law and Order Exhibit Catalog, 2004. Out of print. Thompson Collector's Association program for the exhibit of Thompsons at the NRA National Firearms Museum. 36 pages. I include this one because it is a great, color program that has a lot of history and information on rare Thompsons and other Auto-Ordnance items, and spans the history of the Thompson.


Thompson Manuals, Catalogs, and Other Paper Items, by David Albert and Mike Sig, 2005. Self Published. Currently available from the owner of this website, contact dalbert@sturmgewehr.com. 50 pages. This is a specialty collector guide to the paper items associated with the Thompson, and documents 107 different items. Useful in determination of reproductions, and with knowing what paper items are out there to collect.


The Ultimate Thompson Book, by Tracie Hill, 2009. Collector Grade Publications. Published in April, 2009. The best single resource in existence on the Thompson Submachine Gun, as its title implies. Currently available. ISBN 0-888935-496-0.


Great Britain - The Tommy Gun Story, by Tom Davis, Jr. 2015. CreateSpace Independent Publishing Platform, 2015. Impeccably researched book on British Thompsons, with a particular focus on Savage Thompsons. ISBN 1502977818.



American Thunder, Third Edition, by Frank Iannamico, 2015. Chipotle Publishing. Avalaibale here: http://www.machinegunbooks.com You must have this book if you have any interest in military Thompsons. Enough said.


Doug Richardson's Thompson Book Series: Doug Richardson has self published a series of 7 books on the Thompson Submachine Gun. They are pictured below. The box magazine and drum magazine books are especially helpful references. These books should be considered by the advanced Thompson enthusiast, or by someone with a special interest in a particular subject that Doug Richardson has covered in any of the books.

Thompson Submachine Gun Box Magazines, by Douglas W. Richardson, 1995. Currently available from the author. No ISBN noted. 56 pages. Thompson Submachine Gun Drum Magazines Types "L" & "C", by Douglas W. Richardson, 1996. Currently available from the author. No ISBN noted. 118 pages.

Thompson Submachine Gun Suppressor, by Douglas W. Richardson, 1996. Currently available from the author. Details an aftermarket suppressor designed specifically for the Thompson Submachine Gun. No ISBN noted. 25 pages.

Thompson Submachine Gun Patents, by Douglas W. Richardson, 1996. Currently available from the author. Reprints the U.S. Patent Office patent paperwork for many patents covering the Thompson Submachine Gun, also patent markings on TSMG's. No ISBN noted. 122 pages.

Thompson New Production Semi-Autos, by Douglas W. Richardson, 1999. Currently available from the author. Speaks to differences between the West Hurley Semi-Automatic Thompsons, has operating instructions, and directions about mating certain WWII parts to semi-auto guns. Also mentions Kilgore's purchase of the right to manufacture the Thompson Submachine Gun in 1949. No ISBN noted. 29 pages.

Thompson Technical Volume I, by Douglas W. Richardson, Individual writings on various Thompson subjects dated 1991 - 1999. Currently available from the author. No ISBN noted. 102 pages.

Thompson Technical Volume II, by Douglas W. Richardson, Individual writings on various Thompson subjects dated 1995 - 1998. Currently available from the author. No ISBN noted. 101 pages.


One more book...I forgot to include this one in the group picture...

Small Arms Identification Series No. 17, .45 Thompson Submachine Gun, by Ian Skennerton, 2003. Good overview of WWII Thompsons, with some Australian focus. Currently available from the author. ISBN 0-949749-46-X. 48 pages.

Book reviews and pictures above by David Albert

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