Third Party Press

MP40 silencer

Absolut

Senior Member
Came ahold of this one and thought I should share it since there is nearly no literature nor pictures available on a silencer for the Maschinenpistole 40. Note this model is with rubber shims that was referred as the "Russian System" by the Germans since this was the design of the Russian Bramit silencer for the M.91/30. The German system as well always consisted first of a larger gas chamber (to allow the gases to expand), then the bullet goes through two rubber shims which have a second small gas chamber between them. The shown silencer is incomplete in that it is displayed with only one rubber shim, but there would need to be two (and of course the one shown is a reproduction - I'll need to get a few in proper size).

Rubber Shim silencer have one issue: due to the rifling of the barrel which gives the bullet a right hand twist the bullet gives some of this movement also to the rubber shim through which it travels. This could therefore result in untightening of the silencer itself. Therefore Germans use left hand threading since you need to be able to open the silencer since the rubber shims are consumables and will need to be replaced from time to time. With the K98k and MP44 they used the Gewehrgranatgerät (GGG) coupling which anyway locks around the front sight base (last picture shows an additional comparison with a K98k rubber shim silencer with this coupling), but with the MP40 they have had the problem that due to the rest under the barrel this can't be used. So they decided to use the original muzzle threading with an additional clamp at the rear which fits the front sight and then can be additionally tightened.

The particular silencer here is void of any markings. This is nothing uncommon with German silencers; I have others for the K98k with metal baffles which are also void of any markings. And while we are with this topic, the silencers with the rubber shims generally tendended to be much more effective (meaning less loud) than the ones with metal shims, but the ones with the metal shims had less influence on the precision since the bullet did not had to pass through rubber.

Back to the history: it seems the silencers made for the MP40 were generally metal baffle systems since the only ones officially introduced had them. But there were also experiments done with rubber shims, as proven by an original document: https://www.mp40.nl/index.php?page=photo&pid=4231 (translation of German text under the picture). At my best guess this system never got officially introduced (note the document speaks of no useful results with rubber shims) and therefore the silencer I have might be one of very few left in existance.
 

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This is a unique intersection of my firearm interests. Have you shot the MP40 with it? Does the increase in back pressure lead to extra wear on the bolt and reciever? This design seems like it would be really loud. The bore size of the exit (even with the rubber wipe) looks a lot larger than 9mm. There is not much volume and it looks like there is just one baffle. I bet the hot loaded 9mm ammo is still loud. Maybe this was more to reduce muzzle flash? Pour a little water in there and I think your flash would go way down. Wonder if they had subsonic 9mm ammo?

It is interesting to note that wiped supressors are still popular to this day. This looks a lot like a modern 9mm K can. Google Dead Air Wolfman in short config and they are pretty similar, just a difference in baffle stack.
 
Really interesting, I've seen the Russian one in your last picture - but never the MP40 designated one, here - great stuff.

You think it could have been a sterile post-war/Cold War type thing for use by com-block satellite nations?

Thanks.
 
Now that's a nice and very interesting bit of kit, I didn't know these existed so thanks for teaching me something! It would be interesting to do a test with standard and subsonic ammo to see how it performs.
 
Well, it was so unique that I thought I have to share it ... but to the questions: no, I have not shot with it. Not yet, since I just got it, and not yet since it is missing one rubber shim, as well as that I'll first try to find out whether they used subsonic ammo for it, or if it was fired with normal ammo. Note that on the K98k silencer with the rubber shims there are rear sight settings for subsonic ammo engravings (I guess a normal supersonic bullet might had resulted in serious damage). So I can't speak of additional damage or whatever it might cause. And of course the exit is larger. The rubber needs to have space to deform, but on the other hand to be held enough to not fall out. They surely made thoughts and experiments for the correct size.

Pitfighter, the silencer in the last picture is for the K98k. But of course the "Russian Pattern" as the Germans call it. These are WWII items and nothing post WWII.
 
Thanks for posting. Very interesting.

What does the other side of the rubber shim with the milled out "X" for the 4 flaps look like?

Is it a solid rubber cylinder is it or milled down on the other side for the bullet to pass so the flaps can open and close?

What is the thickness of the 4 flaps?
 
The pictured rubber shim is not the one which was originally with it. It was made to fit and a simple circle shaped cut and therefore cylindrical. I can't tell you if the originals have had the cuts in them as well. For the K98k I know they had rubber shims without a hole, but since the bullets had a pointed tip this might had been different.
 
Pitfighter, the silencer in the last picture is for the K98k. But of course the "Russian Pattern" as the Germans call it. These are WWII items and nothing post WWII.

Nice - looking forward to your further research on it - good find.
 

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