Soo.. issue: Fires on action release
 

Happened to me twice. insert mag, ****/ release and POW.

Any advice here?

Hmmm..apparently I can’t say “C O C K” :D

Is the firing pin stuck sticking out?

Probably sear engagement problem; could be the sear tab on the striker, the sear bar, or the sear spring.

Or like Jim said, striker stuck.

Tell us more about your specific pistol, model? matching? First time out? Worked ok before?

Otherwise, we'll have to use the Ouija board. ;)

It’s a 1936 S/42- been chasing #33 parts for recently. Turns out the danged trigger don’t match either... so I’m giving up on that.

Pin is retracted.

I have recently repurchased the pistol, after about 3 years. I did not have the issue before. Was not shot a ton by the other owner...maybe 250 rounds he said.

did you take it apart and clean the firing pin and inside of breechblock?

Also, swapping in new parts, even numbered the same is still different parts than left the factory. Each part is liable to be hand-fitted at the factory, so even tho the same number, its not the same parts...

Rich,
Take the side plate off and put it back together.
UNLOADED, try the action as you describe- does it hold back the sear?

You can tell by pressing on the sear bar plunger with a stick or something, it should go snap.
While you are pressing, check to make sure the little plunger moves freely.

If the sear contact points are worn, it is more likely to be the sear bar itself in my experience.
Take the sear bar out and clean it and its recess well, could be some junk in there.

If not- keep digging; if so, might be the trigger or side plate/lever fit.

If you have another functioning luger, swap the upper to another frame and try it; and vice-versa.

If the striker is not stuck with the pin exposed in the breech, it's slipping off the sear bar.

This area is complex and hand fit.

Start by checking to see if the little plunger and it's spring at the front of the sear bar is functioning properly. No resistance to being pushed in and springing back out. This is the disconnector. If it's not pushing in properly it could be tripping the sear.

Check ot make sure that the trigger plate is being held flat and solidly against the side of the receiver and frame.

Make sure that the sear is properly seated.

Verify that the sear and the mating surface on the firing pin are sharp and true. Wear or an improper angle or someone's attempt at "improving" the trigger might have made it unsafe.

This work is an area for an experienced Luger gunsmith. Very few regular gunsmiths have ever dealt with the complexity of this trigger system.

And see if the sear return spring is not broken or missing.

I had this problem and found powder fouling on and in the breachblock caused it. I deliberately let the pistol get filthy to see how much it could stand. When it fired on closing I took it apart. It required about 400 rounds to reach this point. The firing pin and breachblock inside were coated in fouling and partially burned powder. The entire breachblock was sticky. Cleaning solved the problem.

Is the firing pin spring present and correct? Is the firing pin spring retainer locking correctly into the breachblock ?

But something is hitting the primer, at least when the breech closes. Is there a mark on the primer (I would think there must be) and does it match the firing pin tip?

If the firing pin is setting off the primer when the breech closes, then at least part of the problem is failure of the FP to reset. Testing with snap caps should confirm if the FP is reseting or not.

As an example of a reset issue, I once installed a new side plate and trigger lever and found the firing pin would not reset. The culprit was the trigger level was new, and did not have the correct bevel to engage the plunger properly. Filing a bevel on the trigger lever fixed the issue. My point is, you'll have to carefully investigate if the FP is resetting.

Firing on closing action
 

I have had this happen on two different Lugers. Both times swapping to a spare sear bar corrected the issue. Too bad on one of them because it had a beautiful trigger pull before correction, and a terrible one after! Better to be safe, though. WB :thumbup:

Interesting, I have to wonder if the nice trigger pull was due to the sear just barely engaging the firing pin tang, and then with a tiny bit more wear it failed to engage at all.

That you've had two do this makes me want to inspect my shooters to make sure nothing is about to wear away - I do not wish to experience a full auto Luger.

Yes,
that would be the primary reason; or gunk keeping the sear bar from returning to its rest position.

Baring a failure, a light trigger pull is a sign of limited sear engagement; so a good area to keep an eye on- but I would not expect significant wear in "normal" shooting. After all the sear surfaces are hardened, it is when someone gets busy with a file or stone and removes the hard surface that problems start. One will frequently see a used sear bar with the catch area rebuilt.

Well..it says something that it DID NOT go full auto tho, correct?

Sounds like I need a pro to be honest. I don’t want an unsafe weapon. And I’m not at all competent beyond basic firld stripping/cleaning. I will take ‘er down and have a look for “gunk"

And you know..this was a refinshed war prize... it came without a pin as I recall... Hmm...

I've had good luck sending Lugers off to our own LugerDoc for repairs. It's simple and easy, and don't tell him this, but inexpensive too.
Do not trust your local gunsmith to repair a Luger as very few have the experience required.
dju

Or the parts, Doc does.

If you are not mechanically inclined, and not comfortable diagnosing/treating your "sick Luger", then look to a Luger Specialist. You will be $ ahead.

Sage advice. Thor DID drop me a PM, but it sounds like he’s not doing alot of work any more.

LugerDoc... I’m gonna clean it up very well and check it out. Will advise. Are you an FFL holder? That would make it easier, but of no consequence. I will of course cover any additional fees should it be required to send.