U.S. Ordnance proposed change of M1921 barrel to M1928 - photo from National Archives

[reconbob]

    Found in Doug's papers - This is a print of a Ordnance Department B&W photo (Negative #A-692) showing a M1921 barrel with small compensator and corresponding small diameter of barrel where the comp screws on. This is barrel "A" in the photo and is labelled a "standard" barrel. Barrel "B" is what we now know as a M1928 barrel and comp with the larger diameter and longer comp and the large diameter of the barrel where the comp screws on. This is the "proposed" barrel. It's too bad there is no date on this, but it is (I think) interesting.

Bob

Edited October 29, 2025 by reconbob

[Arthur Fliegenheimer]

Bob,

Outstanding contribution to the discussion of new barrels manufactured for the Cutts Comp Type II to be installed on the Colt TSMG . The cove for the Cutts pin can be seen on the thread of Barrel B. The comparison demonstrates how a 1921A  barrel where the pressed on ring sight  is replaced with  a Cutts Comp Type I could never be retrofitted to accept the Type II.  

[TD.]

Bob,

A great photograph. Doug Richardson published this photograph long ago and stated it was a 1932 Ordnance Department photograph. I have the complete photograph. The information block at the bottom right hand corner of the photograph is marked "II/I/32" in Times New Roman or similar font. I believe this marking is where Doug decided it was a 1932 photograph. And he may be correct. 

Isn't this about the same time frame the Type 2 compensator was introduced?

Note the top barrel fitted for the Type 1 Compensator has 29 fins. This is exactly the type of barrel you would expect to find on an original 1921A or a 1921AC with a Type 1 Compensator. 

The bottom barrel has only 28 fins and is threaded for a Type 2 Compensator. My guess is this is an early production or experimental Remington barrel for the Thompson submachine gun. It is marked "Proposed Type" in the bottom right hand corner description. Note how the Type 2 compensator appears void of any markings, another indicator this is an early picture (and compensator). I believe most, probably nearly all, of the Remington production barrels have 29 fins. 

I don't disagree that an original 1921A barrel with the ring front sight cannot be fitted with a Type 2 compensator. But I also don't fully accept this statement as 100% absolute. What I will state is it makes no difference as to originality of a Colt Thompson as long as the work was done by or for Auto-Ordnance Corporation in the 1930s. 

What I noticed over the years is the witness mark on the barrel collar on some Colt's with Type 2 compensators are a good indicator the barrel has been updated by Auto-Ordnance to fit a Type 2 compensator. Are the Colt's with "new" barrels any less original? No. Shown below is a 12,000 Colt with what I believe to be an updated barrel. Note how the index mark on the barrel collar does not go across the entire barrel collar and appears to have been applied after the barrel was installed. Note this barrel has 29 fins. 

  

What does all this mean? To me, it is just another inspection point on the many Thompson submachine gun variations. The quality of reproduction/replacement barrels are very good today. I have to give a hard look at the finish of the barrel and if the wear on the receiver, wood and compensator match the wear on barrel. 

All comments welcome! 

[Taliaferro]

I know I sound like a broken record, but please read pages 302-311 Volume one of The Thompson Encyclopedia. 

You will find the whole story. Thanks

 

Tracie Hill 

[Arthur Fliegenheimer]

Hill has this barrel thread gauge (see below) in TUTB that is described as a tool enabling assemblers to match up the witness mark on the barrel to align with witness mark on receiver. Ostensibly this would eliminate anything but near perfect alignments using factory barrels. The question is whether this gauge is of the  Colt era TSMG  or WWII Savage/AOC era. But if this was not available  or used before WWII why not if it is near foolproof simple  method?

The above A barrel had the original ring sight pin cove machined down before the new threading. Is the new cove for Cutts Type I pin visible on the underside of the barrel as is seen on barrel B?

[anjong-ni]

The one would wonder what they would do if it DIDN'T "align perfectly"? 

Can't "back it off"

Trim the barrel shorter until it did aligh?

If the lines went just A LITTLE too far, with that coarse thread, they'd have to lathe-off 1/16th.

Then try it again? I don't think they had that kind of time for such ephemera....       Phil

[gijive]

20 hours ago, TD. said:

 

Isn't this about the same time frame the Type 2 compensator was introduced?

 

  

 

 

Yes, 

That is the year that the Type 2 compensator was introduced,  I believe that is the date of the picture.

[Arthur Fliegenheimer]

Which of these is not like the others?

Colt Chopper posted his collection  of barrels back in 2020. The bottom one,  which he doesn't guarantee being an original 1921A barrel, is threaded for the Cutts Type II. Outside of the thicker collar it is identical to the barrel B picture  that Doug Richardson found in the National Archives. We do know the collar thickness varies on original 1921A barrels.

The answer is...there is no identifying feature that betrays the 1932 barrel from a 1921A barrel (aside from the early barrels with serial numbers) regardless of the 10 year separation of manufacturing. But how did the machinists deal with the pin cove left from the pressed on ring sight when threading the boss for the Cutts Type II?  Did they thread over it? How would that affect the position of the Cutts on the barrel for the new pin? Or would that be addressed by ignoring the existing cove and drilling a second cove?  Has anyone encountered two coves on a barrel with Type II Cutts?  

 

[Doug Quaid]

On 10/30/2025 at 8:42 PM, anjong-ni said:

The one would wonder what they would do if it DIDN'T "align perfectly"? 

Can't "back it off"

Trim the barrel shorter until it did aligh?

If the lines went just A LITTLE too far, with that coarse thread, they'd have to lathe-off 1/16th.

Then try it again? I don't think they had that kind of time for such ephemera....       Phil

what I don't know about building guns you could fit into yankee stadium if you wrote it small

but I have to think that once you got into the zone where the lines match up, the torque on the barrel would be in an acceptable range

like if you are 1/16" below the line or 1/16" above the line, you're in the range of acceptable torque, so you're free to nudge it CW or CCW until the lines match

if the barrel had just one acceptable torque number and it had to be hit right as the lines snugged up, it would take really, really precise machining to do that

maybe recon bob will weigh in since he actually builds them

actually now that I think on it, I seem to remember someone saying that if you remove and reinstall a barrel, the barrel is looser.  that would imply that you are in the plastic deformation level of stress on the threads or collar a little.  once steel is in the plastic range, the stress stays the same as the stretching increases.  which is in keeping with my guesswork above about being able to adjust the rotation of the barrel a little

 

Edited November 1, 2025 by Doug Quaid

[TD.]

And then there is NO 147 from the Cleveland Police Department. Definitely an early Colt with a wedding band for the 29th fin and the assembly number on the barrel visible in the chamber. Many a Thompson enthusiast over the years has pointed out the barrel is not original because NO 147 has a Type 2 Compensator. Many still think that a Type 2 compensator cannot be installed on an original 1921A barrel after removal of the ring front sight. NO 147 is the perfect example that this installation is very possible. Many of those same naysayers also believe Freedom of Information Act (FOIA) information is a waste of time. Thankfully, Colt Chopper (the owner of NO 147) is not in that camp. A redacted IRS Form 1, Registration of Firearms, dated April 3, 1936, for NO 147 on question 9, "Other marks of identification," reveals the following: "Equipped with a Cutts compensator in 1936." Also noteworthy is an Auto-Ordnance Edition of 1936 Handbook that has been with NO 147 since it left the Cleveland Police Department in 1986. More historical information about NO 147, including many pictures, is featured in the last chapter of: Thompson: Colt's, West Hurley's & More.  

How in the world did Auto-Ordnance install a Type 2 compensator on NO 147 when enthusiasts over many years believe it could not be done. As Tracie Hill stated above, the answer is in Volume 1 of, The Thompson Encyclopedia. Auto-Ordnance most likely did not install the compensator on NO 147; Fenn Manufacturing Company, Hartford, Connecticut, did the install - without removing the original barrel from the receiver! 

All good stuff!!!

 

[Arthur Fliegenheimer]

On 11/5/2025 at 8:20 AM, TD. said:

 Auto-Ordnance most likely did not install the compensator on NO 147; Fenn Manufacturing Company, Hartford, Connecticut, did the install - without removing the original barrel from the receiver! 

 

AOC's  difficulty in removing  1921A barrels without damaging them was a thing in 1926 not by 1936 when #147  was sent back to AOC/Fenn  for the Cutts Type II fitting.  With the availability  of 1932 manufactured barrels, Fenn must have been  routinely removing 1921A barrels to install the new barrels made for the Cutts Type II Comp. It is not a  certainty that #147 barrel wasn't removed when the Cutts Type II was installed on it's 1921A barrel. Your pics of Colt Chopper (Jack Meador) #147 barrel/receiver witness  marks are within the same alignment as new 1932 barrels fitted with Type II Cutts Compensators .  The Fenn installer's guide mark is a new wrinkle as well. The Cleveland PD wanted the brand new Type II Cutts fitted to the by then (1936) fairly used 1921A barrel because the $20 added cost of the 1932 barrel was prohibitive? Surely there was no consideration in maintaining the original barrel because of the obscure matching serial number. 

 

[TD.]

Arthur,

AOC's difficulty in removing 1921A barrels without damaging them was a thing in 1926 not by 1936 when #147 was sent back to AOC/Fenn for the Cutts Type II fitting.  There is nothing to suggest Auto Ordnance employees needed to remove barrels after Fenn Manufacturing became a vendor installing compensators. 

With the availability of 1932 manufactured barrels, Fenn must have been routinely removing 1921A barrels to install the new barrels made for the Cutts Type II Comp. While the customer could certainly opt for a new barrel during the compensator upgrade program at AOC, there is nothing to indicate a new barrel was mandatory.  

It is not a certainty that #147 barrel wasn't removed when the Cutts Type II was installed on its 1921A barrel. There is no reason to believe Fenn Manufacturing would not use the "clever device" they invented in 1927 that allowed compensators to be installed on Thompson submachine guns without removing the barrel. 

Your pics of Colt Chopper (Jack Meador) #147 barrel/receiver witness marks are within the same alignment as new 1932 barrels fitted with Type II Cutts Compensators.  The picture from my book at the bottom of page 183 shows the perfect alignment of the index marks on the original 1921 barrel to the receiver of NO 147. 

The Fenn installer's guide mark is a new wrinkle as well. A new winkle, maybe, but we do not know if the mark was made by Fenn Manufacturing or during the manufacturing process at Colt's for this very early Thompson submachine gun. This mark is one of the many reasons I have been searching for NO 190, the sister Colt at the Cleveland Police Department. Gordon Herigstad reports this Colt is also now a 1921AC. My guess (and only a guess at this time) is Cleveland Police Department sent both Colt's to AOC for the compensator upgrade. If I can find NO 190, I will certainly try to get the owner to do a Freedom of Information Act request. 

The Cleveland PD wanted the brand new Type II Cutts fitted to the by then (1936) fairly used 1921A barrel because the $20 added cost of the 1932 barrel was prohibitive? There is no indication any AOC customers ever specified which type of compensator they wanted installed. There is also no indication or documentation a new barrel was required for a compensator install. Yes, a new barrel was available, if necessary, i.e. for a budged or ringed barrel, or if the customer so specified, but no requirement since Fenn Manufacturing invented the "clever device." And for the record, $20 was a lot of money in 1936!

Surely there was no consideration in maintaining the original barrel because of the obscure matching serial number. The barrel on NO 147 with a Type 2 compensator installed in 1936 is the original barrel that left Colt's in 1921. The barrel not only has a wedding band for the 29th fin (found on a number of early Colt's) and is numbered on the chamber shoulder and plainly visible when looking into the chamber. Now, I do believe if an early Colt was sent to AOC because the barrel needed to be replaced (and for a compensator upgrade too) AOC and/or Fenn Manufacturing would not number the chamber shoulder with the matching assembly number. For one thing, they would not have the same marking tools used by Colt's in 1921. That flag on the number "1" in the number 147 seen in the chamber area of NO 147 is without a doubt from the Colt's manufacturing process (picture also included in the story about NO 147).

Attached is a picture you should be familiar with: Note how the number "1" has the flag and the number "4" is very pointed at the top. No doubt the same marking tools as found on the original barrel of NO 147 (page 186).

Thank you for purchasing my book.  

[Arthur Fliegenheimer]

 Never suggested the customer who returned their Colt to AOC was obligated to spend $20 for the new barrel made exclusively for the Type II Cutts. But AOC installed  many more Type II Cutts on in stock Colt TSMG and previously sold Colt TSMG returned for the Cutts. After 1932 AOC was making the decision for customers on which Type Cutts to install. Which method of Cutts installation was the better design and required less time? Machining down the 1921 muzzle boss to eliminate the rIng sight pin grove/cove to accomodate the Type I design - OR - threading the muzzle boss on a 1921A barrel or new 1932 barrel  for the Type II Cutts?

Did Fenn ever respond to Chuck's inquiry with a picture or description  of this "clever device"? 

Is it your belief Fenn threaded the muzzle of the new 1932 barrel and fitted the Cutts Type II  with the new barrel on the receiver after swapping out the 1921A barrel?  When did AOC hit on the same practical and safe method of barrel removal that Doug Richardson manufactured? See photo below.

Not disputing Jack Meador's Colt #147 has the original 1921A matching serial number barrel. As to the "perfect" alignment, judging by the above picture , the barrel line is between the receiver witness line and the scribe line. If this is not the case when viewing the Colt in person then the photo isn't a true representation. Why the scribe unless barrel was off and on for Type II Cutts sight alignment where the scribe marked an initial position where the sight was too far to the left when barrel was torqued down?

No visible additional scribe mark on Colt 1921A #103 receiver. Doesn't seem this was a Colt practice on the earliest serial numbers. See photos below.

[Arthur Fliegenheimer]

5 hours ago, TD. said:

Arthur,

 And for the record, $20 was a lot of money in 1936! 

"Cutts Compensator fitted to Thompson Gun barrel at factory ---(barrel extra)....$25.00" 1936 AOC Catalog.

Cleveland PD was already committed to the today equivalent price of $580. 

Another $466 for the today equivalent of $20 does seem extravagant.  Perhaps the department was evaluating the used condition of #147 when it came to adding the price of a new barrel, yet the AOC advertising proved persuasive to Colt TSMG owners and perspective buyers to pay AOC to substitutes the Cutts for the rIng  sight.. 

[Colt Chopper]

Odd number 103 comes up. I had the opportunity to purchase that many years ago when it was in very poor condition, almost in the white. Lived in Connecticut and was full auto only. It was a coal mine gun.

Probably 5 or 6 years ago I saw it again at the S. A. R show in Phoenix. No disrespect to the now deceased owner, but he was totally convinced that the pretty blue finish was original and was not going to contemplate anything otherwise.

If only the Tommy guns could talk, we would know all the answers to the questions we desire.

Edited November 8, 2025 by Colt Chopper

[TD.]

Not disputing Jack Meador's Colt #147 has the original 1921A matching serial number barrel. I agree and published the same!

If only the Tommy guns could talk, we would know all the answers to the questions we desire. I agree...but then there would be no need for books or this website!

Great information about NO 103. Thank you. Morphy's listed NO 103 in the May 2024 auction and obtained a 30K hammer price. But it probably did not meet reserve because it was relisted in the September 2024 auction. The hammer price at this auction was 26K; sold with Buyers Premium: $31,200. 

There was a 2016 post by joseph12297 about a numbered Colt barrel that was threaded for a Type 2 compensator. It was quite a surprise this was possible at the time. 

 

 

[Arthur Fliegenheimer]

 

Bob, 

Can you differentiate  the sequence  of a barrel boss  first threaded and the  pin grove/cove  drilled after  Cutts Type II Comp was installed and a barrel boss with existing ring sight pin grove/cove that was threaded over to accept Type II Comp?  If the difference  is obvious then this may be the way to identify a 1932  barrel on a Colt TSMG with Type II Cutts.  Of course removing the pin is not an ideal solution when there is a  chance of flattening the head.

 

[Arthur Fliegenheimer]

Colt TSMG  #15025 featured in a SAR article and T.D.'s   An Amateur's Guide for the Colt's Thompson Submachine Gun." 

The photo shows the once dewated #15025 original barrel with partially  unscrewed Type II Cutts. Unfortunately the pin grove isn't visible. According to GH this was sold in 1940 as a 1921A Model.

Doesn't resemble the threads on the 1932 barrel made for the Type II Cutts. Is this a 1921A "H" stamped barrel  threaded for the Type II Cutts? 

[Doug Quaid]

why are the threads so flattened in the above photo?

[TD.]

Gordon's information is not correct regarding NO 15025. According to the Freedom of Information Act (FOIA) packet, NO 15025 was noted as being initially registered as a Model 1928A on an IRS Form 2 on June 30, 1939. The original purchaser is unknown but believed to be a government agency. A subsequent 1972 registration lists the barrel as 12.5" in length.  The dewatted barrel has a Colt era Type 2 compensator.  NO 15025 does have second variation one piece Colt era 1928 actuator.

The "A" marking on the receiver is identical to the 500 1928A's that were sold to the Swedish government in late January 1940. I have seen this "A" marking on a few other Colt's that did not travel to Sweden. My guess is when AOC was preparing the 500 Swedish Colt's for shipment, a few extra guns were marked with the letter "A."  I later found out later the "H" marked barrel is definitely a very nice reproduction barrel. Be informed, there are other "H" marked barrels on Colt Thompsons - not original. When I reviewed the pictures of NO 15025, it was equipped by a West Hurley pinned compensator on what was supposed to be an original Colt Thompson barrel - not. 

I have no idea why the threads on the original barrel appear as they do. Note the one visible end of the flattened compensator pin in the above picture. Apparently, removal of the compensator was not very easy.

This was my first published story for Small Arms Review (SAR) magazine, May 2008. Years later I saw NO 15025 displayed by Kent Lamont at Knob Creek with a copy of my SAR story. Kent told me the original barrel was going to be undewatted using some metal type process and re-installed on NO 15025. That is the last I saw of NO 15025.

How many other 15,000 Colts have survived? I am very interested so please reach out. 

I would really like to speak with the current owner of NO 15025.  

[Arthur Fliegenheimer]

Tom,

Yes, GH does specify the MODEL 1928 with a 1921A barrel. His deviation from the FOIA is that it sold in 1940 not 1939.  What source was GH using that gave near identical  FOIA info?

At some point after receiving #15025 the Government entity owner sent it back to the Maguire owned AOC for the Type II Cutts installation? Or some time between 1940 and 1972  the Cutts was installed? So who  is responsible for the Cutts fitting to the original Colt 1921A barrel before or after  #15025 was dewatted.

Arizona Class Three dealer Tom Stewart  provided you with the photos of #15025 for your 2008 SAR article and that you also used in your "Amateur's Guide", yes? He stated he was able to get the original factory barrel, then fitted with the Type II Cutts, from the seller. Did he tell you why he, or the seller,  removed the Type II Cutts to show the mangled muzzle boss threading for the pic to be included in your article.  

There isn't a complete photo of the original barrel in the publications as only the muzzle with Type II is depicted. Whomever removed the barrel from the receiver replaced it with the repro "H" barrel and West Hurley Cutts Compensator?  Did Numrich rewat #15025 with the "H" barrel and his Cutts? 

Unfortunately all the retro work done on #15025 precludes determining how the threads differ on a 1921A barrel and a 1932 barrel when a Type II Cutts was installed by AOC/Fenn.

Back to Square 1...

 

[M17ap]

H marked barrels 

these are top quality barrels made by Charles Hudak. He was a chemical engineer who

did class 3 as a hobby. He was an excellent machinist and a real gentleman. He was a dealer back in 70’ s 80’s and early 90’s  and made several other smg replacement  barrels in addition to selling guns and parts. He was from Maryland and back in the 70’s he would drive to DC and walk his class 3 transfers through ATF in a couple of hours. Also made some BMG side plates. He later moved to Texas and sadly was killed in a car crash around 1992. His Thompson barrels were Colt quality I know I bought one as a spare back then.

[Arthur Fliegenheimer]

On 4/8/2021 at 10:33 PM, M17ap said

Quote

 

Hey I remember looking foreword to every Issue of Shotgun News back in the seventies. Mostly looking for machine gun ads.

Back then you had to read it cover To cover because all ads were mixed together not sectioned like today. Some guys had 1/4 page ads or 1/2 page ads that stood out. The ones I can remember were LES , C. Earl, R J Perry, Tommy St Charles, Fred Rexer, Chuck Hudak , these were the big guys. Had 10 to 20 guns for sale. There were smaller guys 1 or 2 guns for sale that listed only occasionally where the big guys were regular posters. Sorry if I missed a couple , but these guys were the 70’s. In the 80’s a lot more dealers and collectors popped up and so did prices. Feel free to mention any 70’s guys I forgot. They were great times for the hobby

 

You mentioned Hudak back in 2021. Now you solved the mystery of the origin of the "H" marked barrel. Outsanding!

[TD.]

Tom,

Yes, GH does specify the MODEL 1928 with a 1921A barrel. His deviation from the FOIA is that it sold in 1940 not 1939.  What source was GH using that gave near identical  FOIA info? What Gordon says in his 6th and final edition is NO 15025 "appears to be one of the Swedish order of 500 Colt Thompsons filled in January 1940." While Gordon may think it appears to be part of the Swedish order, NO 15025 never left the USA. While the FOIA does show the IRS Form 2 being filed on June 30, 1939, no copy of the Form 2 was provided. The FOIA information is also not specific as to when it was sold. Gordon is just guessing again. One reason I would like to find the current owner is to have them file another FOIA request. Perhaps additional information by a more experienced disclosure clerk will yield additional information. I know much more about what to ask for than I did in 2007. 

At some point after receiving #15025 the Government entity owner sent it back to the Maguire owned AOC for the Type II Cutts installation? Or some time between 1940 and 1972  the Cutts was installed? So who  is responsible for the Cutts fitting to the original Colt 1921A barrel before or after  #15025 was dewatted. We have no reason to believe NO 15025 was not originally sold by AOC with a Type 2 Compensator. We do know from the FOIA documentation NO 15025 was dewatted "w/Fluted BBL and Compensator." Without further research, I can think of another Overstamp with the letter A mark that was shipped by AOC with a compensator. 

Arizona Class Three dealer Tom Stewart  provided you with the photos of #15025 for your 2008 SAR article and that you also used in your "Amateur's Guide", yes? He stated he was able to get the original factory barrel, then fitted with the Type II Cutts, from the seller. Did he tell you why he, or the seller,  removed the Type II Cutts to show the mangled muzzle boss threading for the pic to be included in your article. No.  

There isn't a complete photo of the original barrel in the publications as only the muzzle with Type II is depicted. Whomever removed the barrel from the receiver replaced it with the repro "H" barrel and West Hurley Cutts Compensator?  Did Numrich rewat #15025 with the "H" barrel and his Cutts? No, not Numrich Arms. While I am not going to mention names, I believe the vendor that rewatted NO 15025 should have known the "H" marked barrel was not original Colt's. 

Unfortunately, all the retro work done on #15025 precludes determining how the threads differ on a 1921A barrel and a 1932 barrel when a Type II Cutts was installed by AOC/Fenn. Retro work? Believe what you want. 

Back to Square 1...

M17ap - Years after my SAR story on NO 15025 was published, I had a reader tell me my suspicions about the "H" marked barrel were correct. He told me the same information you cited in your post. He said Charles Hudak knew his barrels were almost identical to the Colt era barrels so he felt an obligation to mark the barrels. The vendor that did the rewat stated on the repair invoice the barrel was original Colt and charged $1500 just for the barrel. The then owner was not very happy with the work. 

[Arthur Fliegenheimer]

13 hours ago, TD. said:

...no reason to believe NO 15025 was not originally sold by AOC with a Type 2 Compensator. We do know from the FOIA documentation NO 15025 was dewatted "w/Fluted BBL and Compensator." Without further research, I can think of another Overstamp with the letter A mark that was shipped by AOC with a compensator. 

The vendor that did the rewat stated on the repair invoice the barrel was original Colt and charged $1500 just for the barrel. The then owner was not very happy with the work. 

Several reasons to confirm #15025 was shipped without any Cutts Compensator. The non factory boss threading on the original barrel, GH's correct description of #15025 including the "A" stamping and the Lyman sight in meters, and your own March 2011  SAR article on Swedish Manuals where you show their 1939-40 Colt TSMG order specified no Cutts. You also stated  in the 2019 "Amateur's Guide" that  #15025 "may have originally been prepared for sale to a foreign government or customer, perhaps initially part of the Swedish contract."

Does this other 1928A Colt have the identical hideous muzzle boss threads?  Doubtful.

The vendor identity is public knowledge as GH states it was Ohio Ordnance Bob Landies who did the reactivation post 1970. Do you have a copy of GH's final two volume serial numbers?

Your next TSMG publication can confirm the identity of the manufacturer of the "H" stamped barrels. G.E. Hudak Inland Arms Company Austin,  Texas. See photo.