[drbuster]

This may have been discussed before but the presence of the Mauser hump on K date lugers is a fascinating subject. They appear to be solely at random. Does anyone know if Mauser ran several pieces consectively with the hump? Why do some have it and some don't? Was it a maverick experiment that one production line ran? The hump disappears until sometime in the late 1937 year and seem to become a constant feature after the "t" suffix when all parts were blued. The reason for the hump was to prevent falling out of the rear toggle pin with the weapon in full recoil. Why did some workers apparently get this message, find it a good idea and others not in 1934? This is just another feature that makes "K" dates fascinating.

 

[Thor]

drbuster, FWIW I have wondered the same thing. My first variation sn 1594 DOES NOT have the hump.


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[Frank]

I can't answer the question regarding the who, what, where, but maybe the why. As you stated, Doc, DWM (BKIW) were having difficulty with the main toggle pin, not from falling out, but having the head of the pin come out slightly, getting caught on the frame and causing a jam or chipping the pin causing a jam later. This is a photo I quickly put together (hope it works, but maybe Ed can fix it if it doesn't).



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The left image is a DWM, the center a K Date without the hump and the right a K Date with the hump. Notice the rear frame rib on the center image is slightly thicker than the one on the right. This additional thickness would be sufficient to prevent the main toggle pin from extending beyond the frame, thus solving the problem. The right image, showing the hump, retains the rib thickness in the vacinity of the pin, but is thinned in the lower section.

I can't believe they saved enough weight to justify the machining costs of the cut. Perhaps it was a tooling or overall profile issue. This thickness remained through the G Dates, 1936 and into the 1937 production when the rust blue was replaced by the hot dip blue. Then the hump reappeared.

 

[drbuster]

Thanks for your input, Frank. It's all very logical. I guess we will never know why some workers milling the frames got the message and some did not. For what it's worth, my late "K" date, #87xx, does have the hump.

 

[Heinz]

Since the Luger was machined from a forging, would the hump indicate a new set of forging dies in use? If there was a new set and an old set of forging dies the co-existence of humps and no humps would result since you could not machine the hump on a piece from the old style forging die.

What I have always wondered is what else was changed that Mauser suddenly found a need to retain the toggle pin? If the only change is a removal of material in the area below the hump, this change may have been done to modify the forging die for better release of the part or to correct some other problem. TThis would imply the bump is really the original frame length and the dip is the change.

 

[Vlim]

Hi,

Please remember that Mauser received a good supply of parts from DWM when production facilities were moved from Berlin to Oberndorff during 1930. The forged metal part was actually quite a bit larger than the finished piece. John Walter's 1977 "Luger" has a nice photo of the rough forgings of major Luger components from the Mauser collection. Although the forgings are postwar, I think they present a good example of a P08 frame forging in the rough.