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View Full Version : Help me resolve this jam- P.38, made in 1944


Chris_B
May 16, 2009, 05:52 PM
My cyq code (Spreewerk, made in Czechoslovakia in 1944, all numbers matching) P.38 has a jam, maybe 50% of the time, when feeding a new round. A slight rearward tug on the slide clears it every time

I have replaced the recoil springs. I have hand polished the feedramp (with scotchbrite and finger pressure only). I have removed, inspected, cleaned, de-burred, hand-polished (scotchbrite, finger pressure) and reinstalled the signal pin. I have checked the springs in my mags, they seem fine. Mags are clean

And none of this has made a difference. I have tried three mags, including the correct date-code original P.38 mag, and two modern P1 mags. Identical failures to feed.

http://img.photobucket.com/albums/v441/Chuck_Older/jam1.jpg
http://img.photobucket.com/albums/v441/Chuck_Older/jam2.jpg

Its almost as if something is out of 'time'. As you can see, the round is getting trapped under the signal pin. Somehow, the pin is just not traveling up as it should. I have no manner of doubt that without the signal pin, it would work flawlessly. However, that makes it illegal in my location

A P1 as a shooter is also not possible, as that pistol is also illegal in my location. Yes I know it's 99.99% the same pistol. Tell that to Deval Patrick, not me :)

Any suggestions? I have learned one thing today though- putting the slide cover back on is a sumbitch!

Dfariswheel
May 16, 2009, 06:44 PM
I suspect a signal pin and/or spring issue.

I don't remember the signal pins sticking out that far, so either the pin is a replacement, wasn't right to start with, or has been altered or mis-assembled.

Check the spring too, for proper size and length.

Here's an exploded view of the P-38.
Note how the front spring (part B) is orientated, with the "loop" over the top of the signal pin and the rear spring (part I) which fits over the round rear section.

http://www.stevespages.com/ipb-walther-p38.html

Fair warning: Careful with top cover disassembly and reassembly.
Spring the "fingers" on the cover, or get it back together wrong, and the cover will blow off under recoil, scattering parts far and wide.

Chris_B
May 16, 2009, 07:00 PM
Thanks, I do appreciate the help

I am quite sure it is reassembled correctly. I referred to two manuals on dissasembly and reassembly. The primary reference of the two was "Walther P-38 Pistol" by Major George C. Nonte.

The coil spring is in the proper place on the signal pin, and the firing spring pin rides the flat as is proper. The cover was a m*****-f***** to put back on. It is very tight and very flat

The firing pin spring is the "old style". I do have a new style spring in my spring kit but I did not install it, reason being that the pistol is in original military configuration and has no P1 parts to my knowledge at all; all parts are matching but not force-matched, and all parts bear the waffenamt that should have them

It does stand to reason that if the firing pin spring loop is screwy, it will exert too much force on the signal pin though, so maybe I should start to concentrate on that area

I only have experience with this one P.38, but that signal pin does seem to stick out very far to me.

The pistol was a Soviet capture piece, so it is possible that at sometime in Soviet service, the signal pin was replaced with a poorly manufactured one. It was pretty rough on every surface but then again its a stamped part

Chris_B
May 16, 2009, 07:38 PM
I just measured it with my calipers- the signal pin sticks out on the fore end 0.23"

That seems mighty excessive. When a round is chambered, that pin will stick out the back the same amount. It makes no sense that this length is needed to signal a loaded round, and in the dark, nearly 1/4" would be as easy to feel as 1/8"

If the signal pin where shortened 0.050- 0.100" on the fore end, the round would not be at so great an angle plus it would travel further up, and I bet the round would chamber normally

I think your suggestion that the pin is wrong is on the money, Dfariswheel. I can see no functional or logical reason that the signal pin is so far out on the fore end. Simple trig tells me that removing a little length changes the height the round would go up and the angle it chambers at a lot. In addition to being trapped under the pin, I'd wager that the round is at a poor angle to go into the chamber

Chris_B
May 17, 2009, 12:15 PM
When the signal pin is removed, the same jam occurs

With the firing pin out, signal pin out, jam occurs

I polished and de-burred the extractor. Same jam

I have cleaned up a lot of things, had the slide completely detail stripped, and I inspected, cleaned, oiled, and reinstalled everything

Time to stop mucking and go to the range for a function check. No time today but I have Wednesday off work. One's things for sure though- this f'n pistol is clean as a flipping whistle now :)

HammerBite
May 17, 2009, 02:58 PM
There is something about your second picture that has me curious. It looks like the right rear of the barrel hood is eaten away. What's that all about? What does the chamber look like?

Chris_B
May 17, 2009, 03:56 PM
It's not eaten away. It's a slight ding from something. This is a cyq made pistol, which didn't have the highest standards to begin with. But nothing's eaten away, there's a nick on the very edge. The mark at 12 o'clock is from the signal pin

http://img.photobucket.com/albums/v441/Chuck_Older/P38/Chamber.jpg

Dfariswheel
May 17, 2009, 09:16 PM
Things to look at:

Try different ammo.

Check the breech face for roughness or burrs.

Check/replace the extractor.
A sharp or malformed extractor can catch the case and prevent it from sliding up the breech face.

Check the extractor spring and plunger for fouling or an improper replacement spring or plunger.

Check the barrel for a sharp edge right where the feed ramp breaks into the chamber.
This kind of jam is sometimes known as "stemming", where the case is being caught by a sharp or rough feed ramp edge. Just as the case is about to chamber, a sharp break-in edge catches the side of the case.

Chris_B
May 18, 2009, 06:51 PM
I may have resolved it. I just cycled three clips (firing pin not installed) with no troubles. Previously, I had the firing pin and signal pin out, and it would still jam

So I polished the radius of the chamber in case there were burs or an edge. Then I tried again. Still jammed.

I removed the extractor again and inspected it. It was still sharp on the bottom. In fact the extractor was concave on the edge. So I rounded that lower corner, sanded, and polished the whole edge again. Seems OK now

Will range test on Wednesday