Modification of a Standard Upper to .22
 

This thread will provide some insight of the amount of work involved in making permanent modifications to a Luger upper to convert it to .22 Long Rifle caliber.

This is not a project for the faint of heart, or for people whose engineering knowledge is challenged. This is a permanent alteration of a Luger with virtually no return to the original configuration.

This type of major modification should only be done on mismatched parts Lugers.

This thread was inspired by an upper assembly that was originally purchased by Ed Tinker some time ago in the condition in which it is presented in these photos, and hopefully with time, it will include the continued attempt to make this one of a kind assembly a completed project.

Here are the photos that Ed posted in this thread...

http://forum.lugerforum.com/showthre...threadid=18722


http://forum.lugerforum.com/lfupload/img_3638.jpg

http://forum.lugerforum.com/lfupload/img_3639.jpg

http://forum.lugerforum.com/lfupload/img_3640.jpg

My thanks to Ed Tinker for sending me this upper for this study.


...more to come... stay tuned.

First Set of Photos
 

Here are the first 8 images of this .22 conversion attempt from an unknown gunsmith. Take particular note of all the steel that has been removed by drilling and milling to lighten the toggle train for movement by a .22 caliber rimfire... It is assumed at this point that the addition of a properly chambered and headspaced barrel, and a standard .22 conversion magazine that this upper would function correctly... Someday I hope to find out. Comments and suggestions are welcome.

http://www.lugerforum.com/albums/22-...on/100_2370jpg

http://www.lugerforum.com/albums/22-...n/100_2372.jpg

http://www.lugerforum.com/albums/22-...n/100_2373.jpg

http://www.lugerforum.com/albums/22-...n/100_2376.jpg

http://www.lugerforum.com/albums/22-...n/100_2377.jpg

http://www.lugerforum.com/albums/22-...n/100_2394.jpg

http://www.lugerforum.com/albums/22-...n/100_2395.jpg

http://www.lugerforum.com/albums/22-...n/100_2396.jpg

http://www.lugerforum.com/albums/22-...n/100_2398.jpg

8 more views
 

Eight more images of this modification...

http://www.lugerforum.com/albums/22-...n/100_2399.jpg

http://www.lugerforum.com/albums/22-...n/100_2402.jpg

http://www.lugerforum.com/albums/22-...n/100_2403.jpg

http://www.lugerforum.com/albums/22-...n/100_2404.jpg

http://www.lugerforum.com/albums/22-...n/100_2407.jpg

http://www.lugerforum.com/albums/22-...n/100_2378.jpg

http://www.lugerforum.com/albums/22-...n/100_2380.jpg

http://www.lugerforum.com/albums/22-...n/100_2381.jpg

More to come...

The next 8 images...
 

Here is the next installment...

http://www.lugerforum.com/albums/22-...n/100_2382.jpg

http://www.lugerforum.com/albums/22-...n/100_2383.jpg

http://www.lugerforum.com/albums/22-...n/100_2384.jpg

http://www.lugerforum.com/albums/22-...n/100_2385.jpg

http://www.lugerforum.com/albums/22-...n/100_2386.jpg

http://www.lugerforum.com/albums/22-...n/100_2387.jpg

http://www.lugerforum.com/albums/22-...n/100_2388.jpg

http://www.lugerforum.com/albums/22-...n/100_2389.jpg

Still more images soon, stay tuned for additons.

The final installment of images of this conversion. If anyone wants other views of this work, just leave a post here and I will take them as soon as I have time.

http://www.lugerforum.com/albums/22-...n/100_2390.jpg

Note that this upper receiver has NO provision for the standard Luger ejector... which leads me to believe that the upper reciever MAY have been produced from scratch to fit a standard Luger grip frame. It fits perfectly.

http://www.lugerforum.com/albums/22-...n/100_2391.jpg

http://www.lugerforum.com/albums/22-...n/100_2392.jpg

http://www.lugerforum.com/albums/22-...n/100_2393.jpg

Open discussion on this modification work along with recommendations about the steps to finish this mod are welcomed.

John

Interesting. What does the firing pin look like? It does look like a made from scratch,or at least much work on an existing. Appears to be quite old. If made from an original is there anything left to tell from what? It almost appears to be someones prototype? Thanks for sharing. Bill

well, I never looked at it this close John ;)

Very interesting. The guy i bought it from, had bought it from a guy who had 'always" intended to make a 22 luger from it. I think he was a gunsmith and the guy I bought it from said he was a darn good one.


Ed

Bill,
Virtually all markings have been removed. The firing pin appears to be all custom work. I have not disassembled the breechblock yet. The firing pin spring guide and retainer is held in the block by a drift out pin.

Ejection?
 

On Wylon's conversion, the breechblock is relieved to accomodate a lengthened ejector:
http://forum.lugerforum.com/lfupload/22_conversion.jpg

On Ed's conversion, the ejector relief is on the bottom of the breechblock. Could an upper receiver mounted ejector be worked out in this configuration, or must it be mounted on the lower?
http://forum.lugerforum.com/lfupload...ersion_eds.jpg

Jack :confused:

P.S. Sorry Ed, I like Wylon's better!

Experimental Design
 

Hi Jack,

The more I study Ed's .22 conversion prototype pieces, the more intrigued I am about the design and the designer. Of course I agree that Bill Lyon's conversion has an edge since that conversion is finished and functioning (and we know it works!) and this one never was finished. I hope I can come up with the resources to finish this one.

This conversion may have been done one piece at a time. I am sure that there WAS a barrel made at some point, but it long ago was removed for whatever reason...maybe because it was incorrectly machined... who knows.

having mounted these piece in a Luger frame, I have determined that the work that has been done so far has not been without merit. It is pretty easy to operate the toggle by pushing on the bolt face with a cleaning rod, and I feel about the same resistance I would expect in a blowback .22 semi-auto pistol... and that is using the standard 9mm recoil spring. This means that the toggles never have to hit the ramps on the luger grip frame and the pistol would operate as a blowback... very similar in operation to the ERMA .22 conversions.

In answer to your question, could an upper receiver ejector be implemented in this conversion? I would have to answer "no" at this point.

There doesn't seem to be any way for an ejector to be mounted on the upper receiver and work from under the breechblock. It is my best engineering judgement that the original designer of this prototype was going to convert the orignial holdopen as the mounting point for the ejector, and abandon the use of the holdopen feature.

Possibly using a holdopen with an appropriate ejector shape mounted on the stop of the holdopen to ride the bottom of the bolt and kick the empty case straight up.

That problem could be what caused the development of this prototype to be abandoned... It is possible that the bolt face was designed and prototyped first without thinking of how ejection would be accomplished. A poor design in other words. Since the current configuration of the bolt face appears to have been copied from a simple bolt action rifle design and is using opposing extractors.

This method would provide a strong extraction method, but reliable ejection straight up may be a problem with the ejectors at the 3 and 9 o'clock position... I am sure that this is why Georg Luger and Hugo Borchardt put their ejector on the top of the bolt and kicked the empty out with an ejector that hit the bottom of the case.

The only way to know if this system is going to work is to first engineer a barrel that mates with the bolt, and then experiment with ejection being controlled from the holdopen.

I will need a section of .22 caliber barrel of appropriate diameter (about .60 inches or larger) to turn an appropriate barrel to fit in the threaded barrel stub that is already installed in receiver... if anyone has a scrap length of .22 rifle barrel of at least this diameter for me to experiment with, I would be a very willing recipient of the donation. Send me a PM if you or anyone may have an appropriate piece of .22 barrel you are willing to part with... It occurs to me, that a .22 Ruger Mark I or II barrel might be a good starting point. Someone may have one laying around that is left over from a rebarreling project... that would be great.

At the very least, a single shot conversion will be the result of this experiment. One the barrel has been turned, chambered and installed, with cuts for the dual extractors, then the next step will be experimenting with potential ejector designs...

After clearing the ejector design hurdle... the next step would be to kludge together a suitable magazine from an old standard Luger tube and maybe a section of a Ruger Mark I or II magazine inserted inside. I think this would be feeding at the appropriate angle to work with this bolt.

I would love to use a standard ERMA conversion magazine, but they are really expensive to buy for experimental purposes...

I invite questions on the design or these parts... and will post photos as progress is made...

Re: Experimental Design
 

That's what I was thinking... I wouldn't want to be in the shop when our designer had that "Holy C*#P" realization!

With a double extractor, I think it would be very difficult to make an ejector since you would have to tear the spent case from under the extractors that are holding it on both sides rather than prying it out from under a single extractor.

Jack/Ron

I think it may be possible to modify the extractors by reducing their size. By modifying the bottom half of their tips so that their purchase on the cartridge case will be on the top half of the circumference thereby better encouraging straight up ejection by a blow from the ejector at the bottom center. I will carefully modify the extractor tips by shaping them to be smaller (Red areas of the extractors will be removed). Sorry about the crude image, but I don't have any image software where I am, only Microsoft Paint. I hope this image gives you a good understanding of my intended modification.

http://forum.lugerforum.com/lfupload...ersion_jms.jpg

When I get a piece of .22 barrel to experiment with, the testing will begin in earnest.

Scary
 

I'd leave them alone for the first test, then try removing material from one side (in the manner you illustrated). The empty case should kick to the side of the full extractor (the smaller area extractor should let go of the rim first).

This whole breechblock thing is getting scary!

http://forum.lugerforum.com/lfupload...vrsn_scary.jpg

Very Funny Jack! it is even scarier in person.

John
Went to a gunsmith friend of mine. I have 14" piece of a 22 rifle barrel. It is chambered and threaded on one end . Diameter inside the threads is .70+. Will send it to you if you can use it. This is an unfired piece of barrel. He takes them off and replaces with better barrels. It was on a CZ. It tapers down to .69. Bill

EXCELLENT Bill... please check your Private Messages... Thanks for your help.

Another .22 Conversion
 

These photos are of a .22 conversion owned by Patrick Villiers who lives in Germany. The .22 conversion parts are strictly Erma, but the target Bull barrel work looks like very custom work. These photos are located in the "Old Owner's Corner" that is left over from one of the first incarnations of the Luger forum before we came to this format, and created the Member's Gallery.

http://www.lugerforum.com/owner_gall...k/DSCN9622.jpg

http://www.lugerforum.com/owner_gall...k/DSCN9601.jpg

http://www.lugerforum.com/owner_gall...k/DSCN9597.jpg
Photos Courtesy of Patrick Villiers

Here is Patrick's caption for his .22 Conversion:

New Developments in this study.
 

Here is an update to this peculiar attempt to convert a standard Luger upper assembly to .22 Long Rifle.

As I continue to study the modifications made by the original engineering gunsmith for this .22 coversion attempt I am awed by his ingenuity... and left scratching my head by other things...

This image shows extensive modifications to the toggle to include a complete change to the design of the sear/striker/disconnector/toggle linkage:

Point D arrow is pointing at the new Sear/Striker. The sear engagement point is at Point A. The sear has been made an integral part of the breechblock. The firing pin release surface is completely different to match the new sear and the firing pin retainer is held in place by the pin at point B.

The new sear bar is pinned in place at point C and works much like the original sear does on the upper receiver.

The new disconnector shown at point H is identical in operation to the original sear/disconnector engineering except the whole operation has been moved to the breechblock.

Notice that the forward toggle cam is behind the new sear bar at Point G.

Point E and Point F show changes in the geometry of the toggle pin points to allow blowback of the breechblock without movement of the upper receiver. This is the reason for the new sear/disconnector. Without movement of the upper receiver the old sear/disconnector would never disconnect.

The original sear bar has been modified by replacing the spring loaded disconnector pin with a solid non moving pin that has a protrusion that passes the movement on to the new sear bar.

I will make more and better photos of this engineering and update this thread as I find time to disassemble the toggle further.

I still haven't quite figured out the purpose of the spring loaded pin behind the open toggle joint, as it does not engage anything. Perhaps it is a helper to opening the toggle on firing.

More to come as it happens. I hope all you armament engineering enthusiasts are enjoying this reverse engineering investigation thread. :)

http://forum.lugerforum.com/lfupload...380a.sized.jpg

More Engineering photos
 

Here are some new photos of additional parts showing just how extensive this modification prototype really is...

Bottom of the Upper Receivers...(conversion is on the top, bottom is 1937 S/42)

http://forum.lugerforum.com/lfupload/22conv51.jpg

Bottom of the Chamber areas (conversion on the right)

http://forum.lugerforum.com/lfupload/22conv52.jpg

Left Side Rear of the Upper Receiver (conversion on top) notice the roughness of the modifications on the sear / sear spring slot.

http://forum.lugerforum.com/lfupload/22conv53.jpg

Right Side Rear of Upper Receiver (conversion on top) Notice the lack of the ejector opening.

http://forum.lugerforum.com/lfupload/22conv54.jpg

All sides comparison of the sear bars (the conversion bar is on the bottom... dramatic and drastic changes here)

http://forum.lugerforum.com/lfupload/22conv55.jpg
http://forum.lugerforum.com/lfupload/22conv56.jpg
http://forum.lugerforum.com/lfupload/22conv57.jpg
http://forum.lugerforum.com/lfupload/22conv58.jpg

More images next post :)

Another image installment...
 

More detailing of the changes made by this prototype...

The top view of the receiver ring (conversion on the right - like it is no obvious huh? :D ) Also notice the difference in the thickness of the barrel flange on the 9mm barrel and the barrel stub in the conversion receiver.

http://forum.lugerforum.com/lfupload/22conv62.jpg

Changes to to rear and forward toggle linkage. Note the movement of the toggle coupling link and the difference in physical size of the coupling links. The conversion coupling link is much thicker. I am not sure if this link is original or fabricated... but original would be my guess.

http://forum.lugerforum.com/lfupload/22conv63.jpg

Breechblock left closeup. While difficult to see in this photo, the underside of the conversion toggle includes a spring loaded buffer of sorts, that I think contributes to the ability to operate this system as a blowback when combined with the difference in the toggle hinge pin locations, rather than locked breech toggle like the original design.

http://forum.lugerforum.com/lfupload/22conv65.jpg

The right side of the breechblocks. Notice that the original block is round on the bottom and the conversion is flat... probably for proper feeding and clearance working with a .22 magazine.

http://forum.lugerforum.com/lfupload/22conv66.jpg

Notice how the rear end of the rear toggle has been substantially ground down to allow opening of the toggle without moving the upper receiver. This accounts for a major reduction of resistance during the blowback operation.

http://forum.lugerforum.com/lfupload/22conv67.jpg

My next installment should include better photos of the underside of the toggles to show the elaborate spring loaded buffer that was created on the conversion.

I hope this photos essay has been capturing your interest and has been as thought provoking for some of you as it has been for me to do this study.

John
Has been interesting to me, keep them coming. Bill

Thanks for the feedback Bill...

I just learned something new... the conversion breechblock does NOT fit in a standard upper receiver! It goes about 2/3's the way into the fork and screeches to a halt about 1 inch from the chamber... This may be just different tolerance in parts or the conversion upper may have been opened up to accept the conversion breechblock... I will spend some time on this measuring everything with my digital caliper, ... if I can find it! :D It has been a long time since I did any mechanical engineering and I am sure I put it in a very safe place... I just don't remember where... senior moment I guess.

John
If you find your caliper let me know where it was, I may have a simular place where I stored something. At my age looking for something provides many hours of entertainment. I am sure you will figure out how to make your conversion work. Keep in touch. Bill

John
How is the 22 conversion coming? Was just looking at your pictures and wondering what was happening. Keep in touch. Bill

John, you might think about converting one of those redundant extractor slots to the ejector position.

Hi Bill & Heinz

Just a short update... I have splurged and purchased an antique Atlas/Craftsman lathe... that is about 400 miles away... I will have to find a way to go pick it up... and then I will have to spend some time tweaking it so it will do accurate work after the move to VA...

I am going to do this project myself instead of farming out the work.. It will take longer this way, but I think the satisfaction level will be much higher...

I sold my gunsmithing power tools 15 years ago... and have regretted it ever since. Over the next couple of years I intend to own not only a lathe, but a milling machine... all powered by Computer Numerical Control (CNC)... I won't be building guns from scratch, but I hope to be pursuing some very interesting modifications... Stay tuned... this project is far from over.

Thanks for the support Rick... This lathe is exactly the same model as the one I sold 15 years ago... it is manual change gears... and a quick change box would be nice, but I am not a production shop... so I can live with it.

The bed is immaculate! and this lathe hasn't been used much... the previous owner is a retired machinist and he bought it new... now it was just taking up space in his garage... it comes with virutally all the original accessories including the manual... The only repair I need to to (that I know about) is the lead screw support bearing... the owner hadn't used it in years and while checking it out, he turned it on and engaged the table without remembering that he had locked it down and it caused the old lead screww support bearing to break cleanly...

It was designed to to that to prevent lead screw damage in just those circumstances... don't ask me how I know (been there and done that)... the replacement bearings are running from 50-80 dollars on ebay for a used one... but I am pretty sure I can make the original one functional with good ole' JB Weld until I can fabricate a new one out of aluminum with bronze sleeve bearing... I will hold it to the bed with soft aluminum screws so I will have the same type of protection that the old Zamak metal casting used to provide... The screws will shear and neither the bearing nor lead screw should get damaged if something like this happens again to this old machinist gunsmith... :eek:

I will post photos when I get it home sometime in June...

Can't wait to get it home, set it up, get it level, take care of any backlash, and start making 'chips'... :)

John -

The pics you posted to the Rennlist URL's are not showing up here in Lugerforum. Have they been lost? Or does it require registering at Rennlist to view them??? :confused:

Sheepherder... old images restored through the kind generosity and assistance of John D.

Then I extend a big Thank You! to John D. for restoring these lost pics... :thumbup:

Now I will have to read it and try to understand it... :rolleyes:

By the way...How'd it turn out??? :)

Rich, check your PM's ...

I have Lugers and P-38's. A P-38 mainspring will not interchange with a Luger mainspring (it is too small diameter) but MIGHT be used in the Erma unit...Somewhere...

Any guesses where??? :confused:

http://www.lugerforum.com/owner_gallery/patrick.html

I thought you already knew that.

Attachment 43844

I don't have an Erma unit to look at, and the brief description doesn't say which spring was replaced, or if the P-38 spring was clipped...Or why it was substituted...

The salient part of Patrick Villier's comment to me was "The Erma conversion is not all that successful".

For the $500-$600 these kits are going for these days, I'm happy to remain ignorant.

Edit: Patrick Villiers expands further on his comments on Jan Still's forum -

http://luger.gunboards.com/showthrea...n-kits-for-P08

(Patrick is Guest_V).

There are two springs in the Erma toggle; one for recoil, one for the firing pin. The Erma toggle assembly comes apart quite easily for replacing the springs; chasing them across the room can be invigorating...

Maybe Ed Tinker would be willing to try replacing his Erma 'recoil spring' with a P-38 mainspring...The Erma spring is called a 'breech-closing spring' in the Erma manual/parts breakdown... :)

Check with me if you need NOS Erma springs of any kind...

I pulled out my P-38/P-1 parts box and took some measurements -

Mainspring

- .038" wire dia
- .225" OD
- 1.516" free length
- 17 1/4 coils

Recoil springs [two slide springs]

- .026" wire dia
- .207" OD
- 5 1/8" free length
- many coils :p

I don't have an Erma toggle to measure the springs, but I have to say that I'm skeptical of using the P-38 mainspring... :rolleyes:

Rich,

The P.38 mainspring looks like the mainsprings in the Erma KGP series pistols. The P.38 recoil springs look like f.p. springs of that same series, as well as the earlier, cast zinc models. The latter models have actin springs that are similar, but a bit heavier gauge. The springs in the conversion kits are most similar to the latter models' respective springs. I have lots of all these springs, in case you need some.

Dave, I don't need any at this time; I'm just trying to figure out what Patrick Villiers meant about replacing the Erma SE 08/2 kit springs with a 'P38 mainspring'. I don't see how that would work. A chopped-down P-38 recoil spring looks more likely. My experience (in '.22 Long barrel' thread further down in the forum) was that the springs were too strong. Both the Erma firing pin spring and the recoil spring absorb .22 recoil until the firing pin cocks, then it's just the recoil spring. It wasn't recoiling far enough to eject or chamber a round.

The entire cannon assembly has to recoil the ~1/4" in order to line up the magazine with the barrel/chamber. Otherwise the cartridge won't be picked up by the breechblock. The breechblock has to recoil all the way or the spent case won't hit the Erma ejector.

The Erma toggle assembly I tested wasn't going back any further than ~3/4" and with one frame it was binding.

I couldn't do any physical changes because it wasn't my Erma kit and I wasn't about to machine my Luger.

Weaker springs sound like the next step in getting that particular kit to work, but Patrick's comments are pretty discouraging vis-a-vis Erma .22 kits collectively. :(

So when he says the Erma conversion kits are crap, we can take it as gospel? Good! That'll save me $500/$600! :thumbup:

And I'll make a note on my bulletin/work board not to accept any work on these POS's! :D