Calling all Luger experts

[ancient-one]

My daughter has a Luger Po8 1918 Erfurt that belonged to her late husband. The gun is in excellent cosmetic condition. The magazine is not original. For some reason it will go from normal to full automatic fire. The first time was a real surprise but I caught it before any damage was done.
I had a gunsmith(not a Luger specialist) look at it and he said the internals looked to be in excellent condition and he could find no reason for the problem. It did the same for him.
Does anyone have any ideas? Is there any possibility that the magazine could be the problem? It is a good looking gun and would be very desirable if the problem was fixed.
Any help would be appreciated.

 

[diyj98]

I have a couple Lugers, but am very far from an expert. I can assure you though that in no way can a magazine make it go full automatic. One quick thought it that the firing pin may sticking in fired position an not retracting. That should have been easy to check though.

 

[M29since14]

Has the Luger been disassembled and cleaned thoroughly? If not, that's where I would start.

 

[ancient-one]

Has the Luger been disassembled and cleaned thoroughly? If not, that's where I would start.

He disassembled the gun and knowing him I am reasonably sure that he did any necessary cleaning.

 

[murphydog]

If your gunsmith is very familiar with the P08 and thoroughly disassembled and cleaned it...there is obviously still something wrong.

I would have someone who can detail strip it and have the trigger/firing pin engagement surface checked. If there is a problem there it may even fire when closing the action on a live round.

I would guess there is no harm in removing the grip panels and flushing out the internals with brake cleaner, then lightly lubricating and seeing what happens. With two rounds loaded.

Finally, be sure it is really fixed. Knowing you have a full auto pistol, even if it is just broken, can lead to bad problems.

 

[ancient-one]

Just more info. I had fired either 2 or 3 rounds before it went auto. The same thing happened to the gunsmith. The gunsmith was not overly familiar with Lugers. I have not found any locals who are.

 

[LoboGunLeather]

I have owned a few Luger pistols but I am not an expert by any means.

Trigger/sear engagement, disconnector, firing pin freezing in the forward position, probably other possibilities.

Probably most of the gunsmiths familiar with the Luger pistols have retired by now. Perhaps a Luger collector forum with some knowledgeable folks?

 

[italiansport]

This type of problem with lugers is generally associated with the trigger bar assembly. A Luger specialist will have to look at it to determine and fix the specific problem. I'd recommend you log on to the Jan Still Luger forum for specific advice.
Jim

 

[robertrwalsh]

Erfurt's are interesting. They did ONLY military weapons or military overhauls and they are typically described as "*****" (functionally ugly) as their finish was not NEARLY as nice as most of the other makers, which finished their military contract guns to the same level as commercial guns. They are fun guns to shoot and I hope you have luck with it. (My first guess would have also been gunk in firing pin channel or dings on the firing pin itself causing it to jam in the channel.)

 

[CptCurl]

This type of problem with lugers is generally associated with the trigger bar assembly. A Luger specialist will have to look at it to determine and fix the specific problem. I'd recommend you log on to the Jan Still Luger forum for specific advice.
Jim

^^^^ What he said.

Curl

 

[schutzen-jager]

dirt or dried grease under trigger bar ? - remove grips + side plate + try a good cleaning + lube -

 

[farrell]

auto luger

Call bob simpson at Galesburg ill you will find him on the web at simpson ltd.

 

[jake1945]

Simpsons

Call bob simpson at Galesburg ill you will find him on the web at simpson ltd.

They usually charge upwards of $100. Can you take it to their gun shop?

 

[Dvus]

I have a couple Lugers, but am very far from an expert. I can assure you though that in no way can a magazine make it go full automatic...

I wholeheartedly disagree! I have had it happen! If the thumbpiece on the magazine is damaged or loose and protrudes or can be pulled too far out with your fingers, it can cause this issue. Try a different magazine and see what happens. Mine also would go f/a after two or three rounds. My magazines thumb button had split in half and part of it was gone. It would also come out about a 1/4 inch if I grabbed it and just pulled on it. With a new magazine I have not had the problem come back...yet.
On a side note, the Germans experimented with full auto Lugers during WW1, but could not get the cycle rate down where the barrel would not overheat.

 

[2152hq]

Check the trigger bar to firing pin engagement. That's the last link in the multi engagement sear mechanism.
If the trigger bar isn't holding the firingpin in the cocked position as the breech slams shut, the firing pin drops off of the trigger bar and fires the chambered round at that moment and the cycle starts all over again,,F/A fire.

The trigger bar spring (flat spring) could be too light weight (replacement)
There could be debris under the sear bar in it's cavity in the frame not allowing it to seat deep enough. The result is it can't engage the firing pin fully.

The small trigger bar plunger and spring at the front end of the trigger bar might not be working. That's the disconnector of the system and allows the trigger bar to jump back and re-engage the sear edge on the firing pin after a shot.

The sear edge itself on the bar may be worn over (not sharp or shaped correctly) and unable to hold the firing pin securely.

The firing pin has a very shallow opposing sear edge on it's left side that the sear bar engages. Also check that sear edge for wear, chips, damage or alteration. The firing pin should have a ser# on it matching the pistol frame if orig.
Remove the FP by pushing in the FP bushing/guide with a screwdriver placed in the slot in the bushing,,turn the bushing 1/4 turn to release it against the spring tension and allow the bushing, coil spring and the Firing pin itself to back out of the breech block.
(The screwdriver blade tip on the Luger loading tool was for this)

You can check some what to see if these sear edges and springs are OK by doing the following.
WITH THE PISTOL UNLOADED>>
Remove the magazine
Pull the toggle breech all the way to the rear to cock the pistol and let the toggle down easy. Confirm that the pistol does in fact cock by dry firing it. (one of the few times I would dry fire a gun).

Now do the same operation cocking the pistol but this time let the toggle snap forward with it's spring tension alone driving it.,,Let it slam forward and home on it's own.
Now see if that slam forward has left the pistol cocked (will it dry fire?) or is the pistol now uncocked? (the slam of the breech fired the pistol by knocking the triggerbar & trigger out of engagment from the impact).

Try it a few times to confirm, but still inspect the parts above even if it doesn't jump off the sear bar.

That's about all I can think of right now on long distance.

 

[STCM(SW)]

I wouldn't dry fire a luger with out a dummy round in the chamber.
Can damage the firing pin.

 

[DWalt]

From another forum:

Take the gun apart. Under the side plate you will find a right angled crank lever called the trigger lever. Examine the upper end closely. Look at the rear edge of the upper end for wear. The disconnector is a small spring loaded plunger in the front end of the sear on the side of the receiver rail. Make sure it moves freely. Look inside the rail and check the sear for wear. Remove the striker and check the sear engagement on its left side for wear. Make sure everything is clean and properly lubed.