A Learning Experience...

[Navy]

All,
Am in Louisville KY attending SOS and Gunday shows. At the Gunday show yesterday I scored a very nice KM rig, a 1940 dated Code 42, in about 97% condition, Ost See pantograph marked with one matching mag, an armorer's code 42 mag and a code 42 tool, all in a lovely Curt Vogel 1939 dated KM holster. I was one happy camper. The sheep-dip nature of the show -crowded beyond belief-precluded my doing my normal disassembly inspection prior to purchase, so I just gave the markings a peek with my loupe and went for it. It was a little pricey but what the hell.

After dinner, several members of the forum and I were having after dinner drinks when one of the guys took the piece apart. His voice registered dismay when he said, "Look, the witness marks do not align and the barrel does not have a letter suffix.

Well, I thought I had been taken.

This morning, I went back to the show, prepared to have a bit of a chin-wag with the dealer who had sold me this bogus gun.

Fortunately, there were very few people in the hall at the time and I could easily get to Bob Simpson's booth. I showed the piece to Bob, pointed out the "problems" and asked his opinion.

Bob explained to me that the witness marks were placed on the barrel and frame BEFORE the front sight block was machined out of the barrel stock and then the barrel was removed from the frame for further machining, polishing and finishing. After this, the barrel was reinstalled and quite frequently the witness marks would be improperly aligned. In short, this was nothing to worry about and was not an indication of a buggered gun.
Likewise, he remarked that he has seen many, many III Reich era lugers that lacked the barrel suffix.

In short, it was a righteous gun.

I learned something new as a result and avoided a certain to have been unpleasant conversation.

My public thanks to Bob and I guess no matter how much we learn about our toggle-tops, we will never know it all.

Just for grins afterwards, I purchased another K-Date Navy from Bob.

Tom A.

[wterrell]

Tom,
Did he cite references for the information of the process of manufacture that he supplied to you? Footnotes?

[Dwight Gruber]

Tom,

I second Wes's question. The topic of witness marks has been nagging at my brain for a while, the explanation is intriguing, and would account for what I think I see with many witness marks I observe. It would be good to be sure.

Maybe Bob Simpson himself will run across this discussion and comment...

--Dwight

[ToggleTop]

Tom,
The purpose of witness marks are just that to witness something. A true machinist can tell you what they are for and they usually line up. I don't dispute Bob's explanation but I certainly wonder about it being correct! What purpose would the marks have if not to indicate the relative position of the barrel and receiver? Does your barrel have the land diameter digits?
It is unusual to find the serial number suffix on a Mauser military luger barrel, as a matter of fact I don't think I have any that does!

Regards,

I am a man of much wisdom acquired through the years as the water flowed in the river.
My wisdom is based on my need to know in my world.
I have no knowledge of your world.
I will leave this earth with that peace.
My Wisdom Is Mine. (Gertrude)

[ViggoG]

Chester,Dwight, Wes, and Ton A,
In all of my 36 Years in the machine shop environment I have never found any reason for witness marking except for disclosing the removal of a part. And if the parts are reassembled properly there should be no discernable misalignment, otherwise the head space will be changed from the original indicated by the "wit-mark".
IMO It just seems strange to me that a knowledgeable person would make a statement that misalignment was proper.
ViggoG

[wterrell]

But the disassembly of the barrel 'after' the witness mark was applied would be unproductive in an assembly plant. It takes longer to re-align it than to strike it. An engineer would demand that this practice cease if it were a normal part of the production of this pistol.
After a witness mark is applied, there would be no further disassembly and the pistol would be shipped.

[Dwight Gruber]

One of the things nagging at my mind abut witness marks are marks which appear to be one strike, but under magnification are offset -just- enough to be able to tell--certainly not nearly the width of the mark, just the edges offset visibly...

--Dwight

[Pete Ebbink]

Dwight,

I, too, have several lugers and seen others in which the barrel witness marks look authentic and seem to have been struck by one blow with hammer & chisel, but the two halves are just a bit off-center from each other. Ths offset is usually not even as wide as half the width of the witness mark itself...

Would an advanced expert as Bob Simpson be wrong with his reported comment ? That is difficult for me to believe...

p.s. Just some wild a** speculation on my part, but...did lugers routinely go back to an arsenal or field shop for a complete disassembly and inspection? Maybe during the service life of many lugers, they had their barrels unscrewed for such an inspection ? Mere speculation on my part...

Regards,

Pete... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />

[ViggoG]

Hi Guys, <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
Just my opinion, But, I feel that the practice of routinely removing barrels for inspection, is about equal to find "All" of the "Missing 45 cal Lugers" in the same yard sale in Podunk ! <img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" />
Is it possible that all of the small offsets are in the same direction ?
Is it possible that the torque of a projectile accelerating through the barrel could make these minute mis-alignments ?
Just wondering ???
---------------------------------------------
After posting the above, I stripped my 1906 AE to examine the "wit-mk",
When examined under a 60 X Binocular Lab Microscope, The marks appear to be made with two different tools. "??????"
The tools have differing widths of wear in the marking edge, the barrel mark shows to be approximatly 90% of width of the breech mark.
To the unaided eye the marks appear to be one continuous mark, however the Photo below shown nothing definate with one exception, in some of the views there seems to show a a slight difference. "????"




Now I'm Really Confused
What can any of you see ??

ViggoG

[Dwight Gruber]

Viggo,

In one of the photos it looks like the receiver end of the mark might have been double-struck. This could be an effect of the photo, however.

Marks like this are another circumstance which currently vexes me.

--Dwight

[ViggoG]

Dwight,
The "Wit-mk" on the breech is struck deeper on the rearward end and the barrel mark is struck very veryÃ?Â*slightly deeper toward the barrel.
This shows best in the upper right photo.
the lower right photo shows the difference as an alignment of the left side of the marks and a slight mis-alignment in the right side that amounts to the difference in the width difference of the two marks.
The appearance of a double strike is an illusion of the lighting and reflections within the slot.
Had I not viewed these marks at "60 X" I would not be so positive.
OT - AS A comment, the lighting problems that you see here are the same illusions that made the Photographs of the high key very contrasting photos made the "Moon Craters" appear to be raised in the center instead of indented until one adjusted their way of thinking of the light directed toward the object.
ViggoG

[ViggoG]

Hi Rick.
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva"> and secondly if one wants a nice strike on the lower surface would the other surface receive a slightly wider mark due to its additional depth maybe?
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Quite true, However, my poor use of Language "FAILED TO TRANSFER MY TRUE THOUGHT"
I was referring to tool point wear, I'm focusing on the rounding of the very Knife edge of the tool.
The point that forms the very bottom of the mark and wears round with use.
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva"> When examined under a 60 X Binocular Lab Microscope, The marks appear to be made with two different tools. "??????"
The tools have differing widths of wear in the marking edge, the barrel mark shows to be approximatly 90% of width of the breech mark.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">This difference leads me to believe that there is a possibility two different tools were used.
ViggoG

[Ron Wood]

You guys are probably going to laugh me right off the planet, but here is my take on witness marks. I have never seen the utility of striking a mark on the barrel/receiver after they have been assembled. What purpose would that serve, other than as Viggo stated to indicate that a part had been removed and/or if the part is removed to assure that it is reinstalled in proper alignment?

I think they might more properly be called “index” marks. I believe that after final machining of the receiver fork, a mark was placed on the bottom forward edge that denoted the exact “bottom dead center” if you will. When the barrel is machined, the front sight block is broached from the forward barrel band and then a mark is struck on the rear flange exactly 180Ã?º from the vertical mid-line of the sight block (or exactly perpendicular to the horizontal plane of the sight block if you want to look at it that way). Once the barrel has been finish machined with the threads cut and the flange formed, the barrel is trial fitted to the receiver, turning it down tightly but not with a heavy torque. The index mark on the barrel should line up within a predetermined number of degrees or linear displacement from the index mark on the receiver. Given good manufacturing controls, I would guess that proper displacement was achieved better than 90% of the time without further machining of the flange. If the preliminary alignment was off, the rear of the flange was either machined a bit further to bring it into tolerance or discarded if it over-rotated.

Once it was determined that the index mark displacement was within tolerance, the barrel was properly head-spaced and the extractor groove cut, again using the index mark as a guide for proper placement. The barrel was then reinstalled and given a final torque to bring the marks into alignment. This assured perfect alignment in the vertical plane of the mid-line of the receiver and barrel, and obtained a solid mechanical compression fit of the barrel to receiver.

I further support this hypothesis by the observation that the frame serial number is applied prior to finish sanding and bluing. However, the barrel markings are applied “through the blue” to match the barrel to the frame after the barrel/receiver assembly has been completed and blued, thus giving rise to the “halo” effect on the barrel markings that is not found on the frame.

The foregoing I believe is a reasonable explanation of the marks. I would address the possibility of a “proper” misalignment by considering that the compression fit was sufficiently strong to permit a slight rotational adjustment of the barrel during test firing to adjust the front sight for windage and bring the shot group to center. Provided the adjustment was very minor, probably less than the width of either index mark, the compression fit would not be compromised. I would further suggest that quality control in the machining and assembly processes would make this adjustment unnecessary for all but a tiny fraction of the weapons produced.

OK, open fire.

[ken d]

Ron:

I completely agree with your hypotheses. This has been my understanding from day one. I very rarely heard the term witness mark until I joined the Luger forum; it was always index mark. My 2 cts.

Regards

Ken D

[Navy]

Guys,
What a wonderful discourse! This is exactly what this Forum is about. We all continue to learn and THINK, occasionally as a result of a member's post being a catalyst.

We may never know the "100%, No BS" answer, but some genuine erudition has been shared.

Tom A

[wterrell]

I disagree with the notion that the marks were applied before assembly of the barrel to the frame. Such process would be totally impracticable, cost prohibitive, and the refuse rate would be astronomical.
It costs quite a bit of money to produce barrels and frames with the tolerances required to accommodate such an assembly process and would be totally unnecessary whenever other assembly techniques with better, quicker results, which are 'no-brainers' can be conceived and executed by any blacksmith.
Regarding the slight misalignment of the witness marks, steel has memory. If you apply torque to steel and mark its position at the time that it is torqued and constrained, and re-measure a year later, you will find that the steel has begun to retreat. This is part of the process which you are observing approx. 70-100 years after torque.
A practice in the oil field whenever disassembling pipe is to deliver a sharp shock to the joint of assembly and the joint will give to pressure and 'break'. Whenever you have torque pressure and repeatedly apply sharp shock (such as explosion of gunpowder) this will aid in the reverse of torque.
Any production technique as illogical as the assembly, marking, disassembly, and reassembly would have to be documented to be believed. It is too fantastical.

[Ron Wood]

Wes,
I respect and value your opinion and disagreement. I consider you to be a very knowledgable individual and normally I would bow to your judgement. But not this time. I disagree with the notion that "Such process would be totally impracticable, cost prohibitive, and the refuse rate would be astronomical". I believe that the manufacturing practices existing during the production of Lugers, from the earliest date, were fully capable of routinely attaining the tolerances required to accommodate such an assembly process.
With sincere regards and genuine respect,
Ron

An afterthought: "Any production technique as illogical as the assembly, marking, disassembly, and reassembly would have to be documented to be believed. It is too fantastical." In the sequence I suggested, the index marks are applied prior to assembly, then partial assembly is performed to gauge tolerences, then disassembly for headspacing and extractor cut, then final assembly. This isn't a terribly complex operation and could be accomplished quickly, expecially since all of it is performed before final torque and disassembly is quite easy.

[wterrell]

In a "production" environment, this practice would never be allowed. The skill was most certainly available, and with "hand-made" items, this method of manufacture would most probably be common. However, the Germans were not backward in production and would have engineered each step of the manufacture process to avoid such counter productive practices.
All I ask is documented proof.

[Ron Wood]

Ain't got none, but that does not invalidate my assertion any more than it affirms yours. Striking a witness mark after assembly serves no purpose (other than giving collectors a century later something to debate).

[wterrell]

"This isn't a terribly complex operation and could be accomplished quickly"
This operation would be totally unnecessary. The barrels would have been threaded and timed using a 'dog' to position the mount of the front sight. They would then have been torqued to the frame and the dovetail cut for the front blade. And then the barrel would have been struck with the witness mark.
Cheap, logical process, with no unnecessary operations.

"Viggo stated to indicate that a part had been removed and/or if the part is removed to assure that it is reinstalled in proper alignment"
This is the purpose of witness marks.