Can anyone ID the unusual shroud on this Thompson?


May 7, 2004, 10:30 PM
Please see the thread referenced below:


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May 7, 2004, 11:05 PM
looks like an ugly suppressor install, to me.

May 7, 2004, 11:06 PM
The British LRDG (Long Range Desert Group) and the SAS used some suppressed Thompsons on airfield raids and such according to stories I've heard from the men who were on the raids in various books. Obviously the barrel-end threads are for the common Cutts Compensator..... the gun has apparently been field-converted with the lowered handgrip and extra threads for a large Maxim-style suppressor, the more common type during WW2. The steel can on the Thompson shown is probably a fill-in for the original suppressor so it can be shot, without necessarily being suppressed.

I can't say for sure that's what it is, but it would make sense. Suppressed Thompsons are apparently out there in very small numbers (probably rusting away in the desert or an arms room) and this appears to be one, just not with the original suppressor! :)

May 8, 2004, 01:10 AM
From the same post on another forum, and for those of you too young to have seen something like this:

"It's a home-made heat sink/convection cooler.

These were supposed to cool the barrel in a similar fashion to the old Lewis machine gun.

When it's fired, the heat was supposed to cause the hot air trapped between the barrel and the jacket to be forced out, and the "suction" was supposed to pull cool air in.

In fact, these things really didn't work, so you never see them anymore.

I'm surprised to see one even used on a gun as recent as an M1-A1 Thompson.

Just like today, people are always trying to customize and "improve" their guns."

May 8, 2004, 08:30 AM
Funeral shroud, perhaps? :D

May 8, 2004, 10:44 AM
I may only be 26 but I've handled a Lewis gun......

He didn't mention anything about anything being INSIDE the can, which is why I discounted the convection-cooling system. Besides, they showed a bare-barrel Lewis and shrouded Lewis had about the same barrel cooling rate I think, sometime around the end of WW1?

May 8, 2004, 01:21 PM
Wierd... Saw a can that looked just like that while watching the History Channel last night. Except it was on an early 20mm cannon that was mounted on an F-86, I think it was a M39 (one barrel, rotating cylinder). Now, of course, I can't find a picture...

Jim K
May 8, 2004, 09:24 PM
Hi, Cookie,

It was a suppressor, but from what you say, it sounds like the guts have been removed so only the outer shell is left. Had you been able to remove it, you would have found that the barrel underneath had been turned down and drilled with a series of holes along and around the barrel.

AFAIK, it was experimental and not issued, but both the British and the U.S. played with them on the Thompson before going to the M3 and the STEN, both of which were more suitable for the suppressed role.

(The TSMG didn't need any special cooling arrangement, especially that model that didn't even use a drum. The Lewis was a different story, but its cooling system was different. Placing a shroud over the barrel that way would have kept in heat and hurt, not helped, in cooling.)


May 8, 2004, 09:31 PM
I didn't know they made a suppressed Grease Gun. Was it an integral suppressor (ala the suppresed Sten and Sterling) or a screw-on type?

May 9, 2004, 09:01 AM
The suppressed Grease Gun had a screwon can over the barrel I think..... I remember reading in the book SOG about the guys of SOG in Vietnam using it and the suppressed Sten MkIIS.

May 9, 2004, 02:09 PM
From the "for what it's worth" department.

I've seen these can-like tubes on high-firepower weapons many years ago.

The ones I saw were home-made cooling devices.

The way they were supposed to work was, when the gun is fired, the air between the barrel and the jacket gets hot and expands.
When firing stops, the hot air continues to expand momentarily, then when it's exhausted, cool air rushes in to replace the hot air, and cools the barrel.

The idea came from the Lewis gun.

In fact, this really doesn't work too well. The Lewis gun actually "pumps" air through the jacket by using muzzle blast to create suction, but the home-made systems don't really function well enough to justify the weight and bulk.

Having gone back and taken a better look and read of the Thompson, I now think it likely it's fitted with what's left of a gutted silencer.

May 9, 2004, 05:48 PM
The heat fins on the 28's worked great along with the cutts compensator. The were removed during the war for cost.

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