P.38 Slide Defeats Double-Action Trigger

[Grump]

Well, unless I pull the hammer back about 2mm first.

Before I get all tedious and measuring engagement surfaces between the two parts, I got a nice postwar Walther P1 slide to put on a WWII P.38, for use as a shooter.

Barrel fits in just fine, all safety functions check out, and the FP launches a pencil just fine when dropping the hammer.

It seems to me (without further examination) that the fit of the slide for whatever reason allows the hammer to come just a bit too far forward, putting the DA notch just out of reach of the sear or trigger bar (been a while since I looked at the inner workings, but the sear was replaced years ago because of the prior owner's clumsy attempt at a trigger job). The hammer is solidly stuck and no amount of hauling on the trigger will make it budge.

But pulling back on the hammer just a bit results in a faint click and the DA works normally from there. At least it's smoother than one on an H&K VP70...

So is there an easy fix for this? I remember the sear as being a real booger to wiggle into the frame... My hope is that it's something really minor or hard to botch like stoning a bit on the hammer notch or the trigger bar.

Thanks!!!

 

[Dixie Gunsmithing]

Well, as you know, they went from a steel frame, to aluminum with the P1, and newer. There is a possibility that something could have been changed, but right now, I'll have to look up the differences, as I've never tried a P1 slide on a steel frame. I'm also pretty sure there was a few slight machining changes too, but I'll have to look at it first.

 

[SIGSHR]

A few years ago when I tried to purchase a Walther 22 conversion unit for my P-38 I was told it would not fit on my WWII steel frame due to the crossbolt installed in the aluminum P-1 frame. Perhaps that's the problem.

 

[James K]

In the aftermath of WWII, the original engineering drawings for the P.38 were lost, so the new Walther company had to reverse engineer the post-war guns from existing specimens. Many parts will interchange, but others need extensive fitting and the firing pin and safety will not interchange at all, being totally different.

Maybe you can get that slide to fit, but work slowly and carefully or you could ruin the slide.

Jim

 

[Dixie Gunsmithing]

I did some research on this, and found that there could be the possibility of a stamped sear in the frame, since it is WWII vintage. They made them from a stamping for a while for war production, where the the DA nose of the sear is made different or thinner. Also, the nose of the sear is rounded off, but at the top, it flattens off. If the hammer was allowed to move forward, then the DA hammer lever, would come closer to the flat portion on top of of the sear itself, and could cause it to bind, or it may need to be smoothed with a stone in that area, and rounded over. If it has the stamped sear, you may have to get a machined one to replace it with, since that area is thicker.


Walther Sear by matneyw, on Flickr

 

[James K]

That could be the problem. Good explanation and great illustration.

Jim

 

[Grump]

Well, that's interesting. The plum-blued finish on this WWII frame does attract a magnet. For some reason I had thought that the color was from the material being aluminum.

Might have to dig a bit deeper into the research here. Similar post over at the P38 forum has brought NO replies yet.

 

[Grump]

GOT IT!!!!

Not sure how much of this is the added material of the hammer being chromed, but turns out the hammer was the problem. Mostly.

Slide off the frame, it made no difference how far forward the hammer was. The DA mechanism worked fine. Heavy like a P.38, but smooth and no catching.

First I found a burr at the rear bottom of the slide, that corner where it cocks the hammer on recoil. The corner of the hammer where the convex curve meets the flat front was showing a but above the frame in the down position, and doing the interference fit thing on the bottom of the slide. Stoned both of those areas and it helped.

But no joy. It would sometimes still catch, less badly, in the forward position every few trigger pulls, then I noticed that the slide was coming up away from the frame when the hammer was stuck. Pulling it back that 2mm let the slide come back down all the way on the frame.

Turns out the bigger interference was the top of the hammer and the bottom of the hammer cut in the rear of the slide, right below the chamber indicator. Relieved both surfaces and now everything works fine even if I'm pressing down or sideways on the rear of the slide.

Got me a shooter now.


Thanks for the suggestions and especially to Dixie Gunsmithing for finding matneyw's lockwork drawing. Great bunch here.