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Suppressed Thompson?

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#1 RichUrich



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Posted 10 November 2003 - 07:44 AM

Does anyone know of or have experience of suppressing Thompsons?

I have a chance to buy a Title II M1a1 Thompson and was thinking about putting permanently mounting a suppressor on it.

Thoughts and considerations?

Rich Urich
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#2 The1930sRust


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Posted 10 November 2003 - 08:06 AM


Doug Richardson (info in the FAQ) produces a booklet on this subject. It includes, I believe, a history of the 1920's Maxim silencer, as well as design info and drawings. Sounds just like what you need.....
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#3 Bisley45


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Posted 10 November 2003 - 08:40 AM

Thompson Submachine Gun Supressor is the book you want from Mr. Richardson. It's not a very big book but has pics of silenced Thompsons and grease guns, and plans for either mounting a Sonics supressor or his own design based on the M3 supressed grease gun. He even included the diagrams for the tools and fitting a horasontal or vertical forgrip. rolleyes.gif I'd like one but I'd have to move from Blaglavitch oppression land (Illinois) to some place with more freedom of thought, perhaps Beruit.... rolleyes.gif

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#4 Bob


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Posted 11 November 2003 - 10:56 AM

Nope, two stamps, two serial numbers...nice try however!

Registered MG and form 1 (w/200.00 tax) to build a suppressor on the end of the barrel you would have to engrave and serialize. Even if you used the same serial number it would be a suppressor serial number.
Same as a CII manufactures a suppressor he will form four to you and you pay $200.00 tax even if it's permanently attached.

ATF will count two separate items unless you plan on suppressing a semi-auto carbine where you may have a problem with the AW ban (flash hider).

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#5 Bob


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Posted 11 November 2003 - 12:22 PM

My quietest I think is a SW76 with a Bixler can, the only thing you really hear is the projectile hitting the paper with a crack.

Humm, wonder if I could make an adapter for my '21/28 that would couple to a PS Mac can??? dry.gif

Now you've done it..you stirred up the dust in the ole brain pan, (I have an extra barrel with threads).
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#6 TommyGunner


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Posted 11 November 2003 - 06:55 PM

Ahhh and here is a pic of such a beast!
user posted image

This is my wife Erika shooting at this years TCA show and shoot. It sounded like a zipper and you could hear the round hit the paper. I kept missing the shot because it would empty the mag before I could go click...happened about 5 times in a row so I gave up! It was very quiet...my airgun is louder. Special thanks to the gentleman in the pic that let her shoot his gun...(sorry forgot his name sad.gif ) Oh and it also had the 22 cal conversion so it was really quiet with a higher rate of fire.

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#7 giantpanda4


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Posted 11 November 2003 - 10:49 PM

This is a quiet unit!
I stood beside it while my son also shot the same gun Tommygunner shows above... and I forgot my ear plugs. But I didn't even realize until someone next to us cut loose with an L drum!

He had a smile for hours about it!
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#8 Doug Richardson

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Posted 12 November 2003 - 01:23 PM

Yes, indeed, I offer a booklet on suppressing the Thompson. Actually, it talks about silencers in general and early Thompson silencers. But it is primarily a booklet on how to build a Thompson silencer. The history behind this booklet may be of interest.

Years ago when MAC 10s hit the scene, the law was that a silencer was not a silencer unless it was complete. MAC 10s were all threaded for a Sionics silencer which screwed onto the gun. The MAC 10/ Sionics silencer combo became very popular. This revived the interest in silencers. It seemed that everyone was cloning the Sionics silencer and trying to fit it to any thing that shoots. A real cottage industry developed of which I became a part. Some people were manufacturing the internal components and selling them as kits. Others, including me, were making the tubes. A person could actually go to a gun show and pick up every part which only needed to be screwed together to complete a silencer. And then there were others who made adaptors to enable the Sionics silencer to be fitted to various guns. I offered a short Thompson barrel that extended just beyond the vertical foregrip which was threaded for the Sionics silencer. It also had an optional sling mount which incorporated an adjustable (windage) front sight.

Two problems soon became evident: (1) Screwed on silencers tend to unscrew themselves during firing. (2) Large screwed on silencers are difficult to align with the barrel bore.

At this point I decided to design a silencer specifically for the Thompson. My design was based on the best two stage silencer designs in use. What was innovative was the incorporation of existing technology into the Thomson gun. I modified a Thompson barrel to a smaller diameter to increase the expansion chamber volume and machined on a step at the breach end to locate the back of the expansion chamber. The muzzle was threaded to accept a bushing which aligned the front of the expansion chamber with the bore and also provided the attachment for the bleed off chamber. This created a very rigid assembly with the maximum silencing in the shortest length. It only added 7 to the Thompson gun. This design eliminated the grip mount and front sight. The grip mount problem was solved by incorporating a grip mount on the bottom of the expansion tube. Since rotation of the expansion tube is possible before the silencer assembly is tightened, the sight can be adjusted for windage. This design did not modify the gun in any way, it simply replaced the barrel and grip mount.

How well did it work? The only noise was the bullet hitting and the cycling of the action.

I started manufacturing kits that had every part but one. By the strangest coincidence the missing part turned out to be a standard Sionics part made by many others.

As has been my experience with many of my products, it soon become illegal and I was forced out of business. The law was changed so that any part to a silencer is a silencer. That being the case, I wrote my suppressor book, documenting my design so that others with the proper license could make them. With so many people getting Class II manufacturing licenses and making guns from my display receivers, I believe that if a gun is being made, it can be made with the silencer as a single unit as far as the paperwork and tax is involved.

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