Ciener's 22 caliber Thompson kit: A new side to Thompson fun
By Dan Shea

While the venerable Thompson Submachine Gun has served the military and law enforcement communities for many years, its day has passed; except in the hearts and hands of the world's Thompson collectors and enthusiasts. The many variations of the Thompson that are found in collector's hands today are virtually all available to civilian owners in the United States; the Thompson in all of its forms is a highly sought after collector's item. Many were registered from 1934 to 1986, and there are many active groups of enthusiasts firing these at competitions or local ranges.

Arguments can be made that firing the Thompson can be prohibitively expensive and that a 22LR subcaliber unit can be more cost effective. Frankly, I don't know any Thompson enthusiasts who are really looking to save money when they consider 22LR. All of them agree that firing their Tommy Guns in 45ACP is fun and has an authentic feel, and they will keep doing so. The desire for a 22LR Thompson Gun kit is to add some new aspects to that fun. 22LR is very controllable in full auto, and in a Thompson it can be fun for the whole family. It makes for a great day at the range, especially for children and others who might experience difficulty controlling a Thompson in 45acp. Ciener's instruction manual is very precise and covers almost all aspects of installation and use. Disassemble your Thompson- remove the lower trigger housing and the bolt carrier assembly. Slide the barrel liner into the receiver cavity from the bottom, keeping the ejector to the outside to have room for maneuvering.

The buyer who fails to read the instructions will quickly be presented with the dilemma of how to get the barrel liner into the chamber area- and that is quickly answered by the manual. It is necessary to remove the original ejector from the Thompson receiver so that the chamber insert will pass that area and key into the chamber extractor slot. Removing that ejector is a task for patience and care- especially with the Colt guns and their fine finish. I know there are some old Salts out there with scratched up military Thompsons they registered in '62, and flat blade screwdrivers they bought the same year- you are welcome to scar your Thompsons. However, for the rest of us, using a thin blade (Non metallic is best) lift the end of the ejector flat and rotate it to the left (This is standard right hand threading- righty tighty, lefty loosey. Stupid rhyme, but, hey, it works for memory). Continue unscrewing the ejector to the left and remove it from the receiver. Now your barrel liner assembly should fit in from the rear of the receiver.

There is one more potential impediment to consider- improper cleaning. If your Thompson is not cleaned thoroughly, you may well have problems getting the liner in place. Surprisingly, even those who have run patches and are confident their Thompson is "Clean" may have a problem. The thorough cleaning of bore and chamber is required to fit any insert to a system, and many standard cleaning practices leave residue built up at the front of the chamber area. It is recommended to use a chamber cleaning brush and I suggest the Otis pull through style of cleaning- get the Otis Deluxe Military Cleaning Kit which includes 5.56, 7.62, 9mm, 45ACP and 12 Ga, but more to the point has the Otis "Long" pull and the 45ACP brush. Pull from the chamber to the muzzle, that should ensure no "Dumping" of trash at the chamber mouth that might block the liner insertion. Jerry Williams at Otis tells me they are coming out with a new "Thompson" kit- long pull and 45ACP brushes and may include their .50 brush for chamber cleaning. www.otisgun.com

The initial testing done by the staff at LMO LLC included the firing of 200 rounds of Remington High Velocity 40 gr. Round Solid nose ammunition, as recommended by the manufacturer. Rate of fire was tested with a PACT Timer, and it was consistently XXX rpm. The end result for the testers was simply pleasure. No problems, lots of fun. That's a pretty good recommendation. One item of note is that Ciener uses an anti- bolt bounce device in his bolt carrier, which contributes to the reliability of the system. Ciener's experience in the tens of thousands of 22LR subcaliber kits he has built for the M16/AR15, AK47, AC556 and numerous pistols has paid off in his current design.

The kit we tested was the "All" kit, which as expected, has "All" of the parts to be used in any configuration of the Thompson Submachine Gun; 1921 with and without compensator, 1928/21 Navy, 1928A1 military, M1, and M1A1. Ciener offers a variety of kits with some lesser parts for each model, and there is some savings to be had in purchasing the model specific kit. However, for the basic Thompson enthusiast, having all of the parts to use in any of the guns is probably the best choice. If your kit is for the 1928A1, and you have a friend with an M1, it is only a couple of hundred bucks to ensure you can shoot his gun in 22LR as well. I recommend the "All" kit, and unless you are a stickler for appearance for your pristine blued 98% Colt 1921AC, you probably won't need to consider the "Deluxe" kit, which adds Hi-Luster Blue on steel parts and Gloss Black anodizing on the aluminum parts. Retail price of the "All" kit is $749-. Magazine capacities available from Ciener are 20 round and 30 round. Kit weighs only 1.5 pounds.

The negatives: hardly any at all. The first one that comes to mind is the restrictions on ammunition use with the kit. Anyone with experience with 22LR machine guns knows they are all very ammunition sensitive and the projectile shape, powder level and a variety of other manufacturing idiosyncrasies keep the 22LR machine gunner testing different offerings until he finds what works best. In this case the Ciener recommended ammunition worked perfectly every time. There was one misfire, and the round had a solid primer hit, the kit did its job, it was the ammunition that failed. Not unusual with 22LR. The second negative is that Ciener won't guarantee his kit in all of the Thompsons that are out there. He excludes anything other than the Colt and Military Thompsons, which leaves the West Hurley and Numrich guns out of his guarantee, as well as any welded up guns. An objective tester has to admit that the West Hurley Thompsons suffer from so many reliability problems and many are so out of spec that it would be unreasonable to expect a manufacturer to be able to keep a product working in them for retrofit. Let's not even touch on the subject of specs on the rewelded receiver guns out there.

Our test gun was a U.S. Military M1A1 Thompson, that had the markings from being rebuilt at arsenals several times. Suffice it to say that old warhorse worked perfectly with the kit, and we would have observed problems if Ciener hadn't done his homework and allowed for some range of tolerances. For those potential buyers who have the West Hurley and non Mil Spec guns, these kits are worth a try, but might need some work to get them reliable if your gun is out of spec. However, that will void your warranty, as it should- no manufacturer can warranty his product if it has been improperly modified and used in a non spec unit.

These kits are a definite must have for Thompson owners who want to shoot in 22LR. They are well thought out, well designed, and properly made to last for a long time.

"Basic" Kit for 1921/28 or M1/M1A1 w/1 30 RD. Magazine. - $499.00
Parkerized/matte black anodized, specify model & w/ or w/o Cutts comp.

"All" Kit for 1921/28 & M1/M1A1 w/2 30 RD. Magazines. - $749.00
Parkerized/matte black anodized, includes parts for w/ & w/o Cutts.

"Deluxe" Kit for 1921/28 & M1/M1A1 w/1 20 & 1 30 RD. Magazine. - $849.00
Hi-Lustre blue/gloss black anodized, includes parts for w/ & w/o Cutts.

Spare 20 or 30 round Magazine - $99.00

Kits are available from your local Class 3 dealer if he is paying attention, and direct from the manufacturer as well:

Jonathan Arthur Ciener
8700 Commerce St
Cape Canaveral, FL 32920
Tel: 321-868-2200
Fax: 321-868-2201
Website: www.22lrconversions.com

This article first appeared in Small Arms Review V8N11 (August 2005)
and was posted online on May 3, 2013


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