Mystery 22 Conversion Kit

Hello all,
I was hoping you knowledgeable fellows could help me out with a bit of a mystery.
I picked up this kit at an auction this weekend. I know it's a 22 conversion kit but I haven't the foggiest what it's for.
The outside dimension of the barrel is 8.8mm so I think it's for a 9mm.
The machined aluminum section has a groove cut in it so I think it slides over the existing front sight.
The clamped band around the machined aluminum section would then serve as a front sight...I think.
Both the shell holder (which contains the firing pin) and the chamber end of the barrel have a 10 engraved in it. Electropencil, looks like.
The box is nicely fitted sliding top box out of maple. The top slides very snugly.

Any ideas?? I really appreciate it.

Couple more pics:
Attachment 86549
Attachment 86550

Measure the "in barrel" length carefully - my guess would be it's for a Luger.

Alright, I took a few measurements:
The barrel measures exactly 8.25" when including the shell holder. Put in other words, if a barrel measured 8.25" from bolt face to muzzle, it would cover this assembly. However, note the two lock nuts -- with these included, the barrel could be, at most, 7-13/16" and, at least, 7-5/8". I suspect these nuts would essentially be used to adjust headspace.
The machined aluminum section measures 4.25" overall length. The opening (which I've presumed to fit over the existing gun's barrel) has an inside diameter of .597".

There's a marking on the biggest round, what is it?

I can find no markings on any of the parts except for an electropenciled "10" on the shell holder and the barrel.

Look at the top picture, you'll see what I refer to...

I believe I see what you're seeing. Nearly in the middle of the biggest round section? That's just a couple small scratches...definitely looks like it could be a hallmark in that blurry cell phone pic though, haha.

Thought I'd add in some more photos. May be helpful to someone else someday even if we don't figure it out now!

HA! I found it! For some reason it dawned on me to Google not for "22 conversion kit" but for "22 subcaliber conversion" or something along those lines. Looks like it's a Leinhard System conversion kit. Check this out:
Lienhard 4mm for the Swiss 7.5mm rifle - General Ammunition Discussion - International Ammunition Association Web Forum
Do a google image search for "kleinkaliber einsatzlauf kaliber" and you will see quite a few pictures.
Unfortunately, I haven't found tons of information and thanks to Photobucket's stupid new rules it's hard for me to match the information with images.
I can't find any of these that have sold on eBay or Gunbroker. My search continues but now in a very clear direction!

Quote:

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Originally Posted by rcathey

The opening (which I've presumed to fit over the existing gun's barrel) has an inside diameter of .597".

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And my Luger has a diameter of 0.585" at the muzzle. A plausible fit, wouldn't you say.

Now please measure the width of the foresight slot. The Luger foresight blade sits on a small block. If that also fits, we're almost there...

---------- Post added at 10:15 PM ---------- Previous post was at 10:06 PM ----------

I just measured my Luger. The foresight block is 0.259 wide. Just for fun, and looking at your photo, I'll guess the slot is about 0.270 wide and would take the Luger foresight block.

... Can you find a standard P08 in 9mm with a 4"/100mm barrel and see it if fits?

---------- Post added at 10:23 PM ---------- Previous post was at 10:15 PM ----------

The P08 was made with various barrel lengths: 100 / 120 /150 and 200 (nominal) mm.
Looking at the kit, it seems that the basic rifled insert tube would cover all these.
To this end, the external aluminium tube would have to come in various lengths - or be adjustable. Is there any sign of that?

The slot actually measures .258" with digital calipers. Pretty tight given your measurement!
The folks at the Cabela's gun library might let me slap this on but I kind of doubt it. Unfortunately, I moved to the St. Louis area relatively recently and haven't yet found a gun store that I even want to establish a close relationship with (like I had back home, I mean).

Don't worry about the apparently tight measurement - I wouldn't trust my supermarket cheapo slide gauge to the last mm anyway! And it was probably supposed to be a tight fit, to stop the insert rotating when firing.

It's for a Luger P08, as I guessed at the start. They were made with barrel lengths of 100, 120, 150 and 200 (nominal) mm. It looks as if you have the version for the standard 100mm army barrel. The rifled insert is long enough to be used with the other lengths up to the 200mm for the LP08 a.k.a. artillery Luger. To achieve this, you will probably find that the slimmer section of the aliminium tube screws into the thicker section with the sight slot. The slimmer section would have been available in various lengths to suit the various barrels.

I would love to have it for my LP08, but I can tell you right now I couldn't afford it! Luger collectors love that sort of thing, and if you got it for less than a 3-figure price it was a good deal.

All this is, of course, just my enthusiastic opinion!

Now go and find a Luger owner (gun club?) and try it out!

Great guess! I thought the same, myself, due to the Luger-esque shape of the aluminum section. I can't tell you how many Google image pages I scrolled through under "luger 22 conversion kit" and similar but nothing like this popped up! A slight change in nomenclature and there it is.

I truly appreciate the help!!


Just saw your addendum. The machined aluminum section is indeed a two-piece assembly. See photo. Looks like the manufacturer could thus machine the thin section for whichever barrel length was required and press fit it into the thicker section. Fascinating stuff!