Gomann Berlin
 

Friedrich Gomann got a patent on the 4. April 1926 for his conversion unit in calibre 4mm M20.
The muzzle protector was refined and used by the Police.
Of interest is the date of the patent because of the acceptance mark which we also can find on the receivers of several Lugers of this time.
Attached are the patent drawings and some photos.

Luger 22 Muzzle Attachment Question
 

Hello all,

I purchased this a few years ago and thought it was some type of Luger training accessory or an extra part with a 22 kit? Anyone have any ideas? It is marked Erma with the Waffen Eagle R stamp on it.

Thanks in advance

From what I have always been told, these have two purposes

1. put on the muzzle and then it can be used to clean from the front and not damage anything on the crown

2. they are used to attach the 22 training for a single shot - I have one of these

Ok that makes sense, I wonder why there is limited information about them on the net? What should one sell for? Thanks again

I have bought them for $50 - $150 - depends on how they are marked

It´s a Police accessorry and was used with an 4 mm M 20 barrel by the Police. A .22 cal. version is commercial.
By the way: the eagle R is a Police acceptance E/B

Edward,
can we see some pictures of the .22 cal. barrel, please.
I could never get one.
Thanks
Klaus

I was not sure but I found one of my older threads about the different types of conversion units.
http://forum.lugerforum.com/showthre...onversion+unit

Here is an example of the police marked ERMA conversion unit. These single shot training units fit the 9mm P.08 by the way.

Very interesting! These sub-caliber conversions lock on the front sight base rather than a chamber lock like the .22 Erma conversions (stepped & flanged barrel insert).

George, is the 4mm cartridge center fire??? I suppose it would have to be... :confused:

Very interesting! Thanks guys

There is/was a 4mm M20 cartridge. And it's centerfire. It has no powder i'ts propelled by primer alone.

Yes, the single cartridge is loaded by hand and extracted with a rod run through from the muzzle. Here is a period description.

George

I have also seen them marked eagle 359 (??) and so I was not of a firm belief if they are always police. I sold that one, the one I kept says S.B. 1703

It has a spring action that you push and then it holds fast to the barrel

Also, somewhere I have a couple of 4mm - my friend Russ had a box of them once. But heavens knows where it is...

Ed,

The military used these Einstecklaufe as well so your WaA marked one was not police issue. Your Schutzpolizei Berlin marked example and mine most certainly are. These are complicated little things and a lot of trouble to use.

George

George, I find that a curious comment...I have fired three different .22 Luger sub-caliber conversions in the past Summer and didn't find them much trouble to use...

Ed's 4-piece 4mm conversion doesn't seem all that complicated either...(Although I would prefer the 4mm muzzle clamp that uses the interrupted rear nut)...

Could you explain further??? :)

Maybe because the 4mm M20 (the one on the left) as no rim and might get stuck after fire.

Attachment 44070

Mario, is the 4mm barrel insert rifled or smoothbore??? :confused: Primer-only ignition can't be all that powerful, even for a .157" projectile...

A barrel insert installed from the muzzle leaves the chamber end unsupported...The Luger chamber is ~.386" dia and the bore is ~.346" dia...So the barrel insert is unsupported at the chamber end by ~.040" total...(.020" radially)...So you can't have too much chamber pressure or it would expand the insert, making it 'difficult' to remove... :rolleyes:

Now you got me. This contraption was popular in Germay where it didn't need registration ( there were pistols exclusively for this type of cartridge either made on purpose or modified ). Here I've never seen one so can't really answer.:o

Apparently nowadays these things must be registered as firearms in Germany. So my guess is they will be headed the same way as the dinosaurs

Edward, it`s a Gomann conversion unit...
http://forum.lugerforum.com/showthre...onversion+unit

I copied and merged the earlier one - if anyone objects, I will change it back...

this is a great thread, thank you - I made it a sticky

Danke Klaus

Ed

Yes, from a police training standpoint the single shot nature of these inserts are not realistic. They are fine for indoor target shooting to teach marksmanship but since they must be loaded and then unloaded after each shot they do not mirror the tactics taught for officer survival.

The goal of police training (when I was such a trainer) was to do repetition drills to intill muscle memory without having to think through the process. Police training is set up nowadays to have polilcemen draw, fire, and recover from a snapped in holster in order to simulate what might happen during an armed encounter. Having to stop and futz with your pistol between shots is counterproductive to such training.

Back in the 1960s dead policemen were found with empty shell casings in their hand after shooting scenarios. This was because rangemasters had allowed policemen to carry their brass bucket with them from one yardline to another. The rangemasters were inadvertantly allowing the officers to instill muscle memory from repeatedly emptying the spent cartridges from their revolvers into their hand in order to throw it into the brass bucket. It got people killed and when instructors realized what was going on the training was changed.

So, from this standpoint these single shot sub caliber units are not conducive to keeping you alive in a shooting. The multi-shot .22 caliber conversion kits do not have this drawback.

George

George, I taught military police firing and did many ranges, nothing like you I am sure. But we did lots of dry fire exercises and it was designed to encourage finger control and accuracy. I think a single shot is designed for that, rather than later police tactics.

Police tactics were designed in the USA - i.e. Street Survival series, learning not to pick up your ammo upon firing (a tactic that was learned at the range in the 50's, 60's 70's by cops), etc.

Just my 2 cents

Quite right Ed, 1930s German Police firearms training was more in line with military training at the time and was marksmanship based. Sight picture, trigger control, breath control, etc. all designed to accurately put rounds on paper targets. Tactics were taught seperately then but they have changed significantly over the years.

None the less, these small caliber units are fun to shoot. I have a .22 caliber conversion kit for my US M1911a .45 pistol as well as having a pre-war Colt Ace in .22 caliber. I love to shoot these since they have the floating chamber and are easy to switch out and clean. I don't know how the German Police firearm instructors felt about the little 4mm single shot conversion kits but they do seem to be a lot of trouble to me.