Thanks Dwight!

Understanding what causes it and understanding Lugers--thats two different things:)

Now I know; don't you just love learning new things ;)

Now if I can just get a grasp on magazines and holsters--naaaaa that may take a while!

Vern

Dwight,
I don't mean to sound nitpicky, but the metal under the halo is stretched. It was flat until the stamp made it bulge upward. The curvature of the metal that was once flat has more surface area. This makes the blue thinner and a lighter color. The metal inside the stamp is compressed, which is why the blue stays there.
Mike C.

Thank You Boys for the information. Now all I have to do check all my Lugers :-).
And is there any list that indicated what was stamped before and after blueing?
Thanks again
Alf

Mike,

Nitpick away. My observation is that the amount of metal which is displaced upward is very small, compared to the area of halo. The halo varies a lot, and I have observed halo which, in area, is two or three times the area of the actual stamp--far beyond what might be expected to be accounted for by localized upwelling.

I reiterate my desire to see a metallurgical explanation of the phenomenon. It would also be interesting to see a comparison between compression and expansion of blued metal.

Alfred,

There is no single list. I think the best compendium, at least for German military Lugers, is found Jan Still's series of books.

In general, most original Luger markings--receiver marks, inspector stamps, serial numbers, worker's marks--are stamped before bluing. This is the same for military, contract, and commercial Lugers. Most barrel proofs, serial numbers, and caliber marks (but not inspector stamps) are stamped after the blue. Some are not, and the serial numbers on model 1900 Luger barrels do not exhibit halo even though stamped after blue. GERMANY export marks are stamped after blue.

Frankly, the before/after blue stamping on Lugers is quite variable. There are other kinds of stamps I have not mentioned, and they may be stamped before or after blue, depending on many circumstances. There have been many discussions on these Forums regarding marking halos, and whether the presence or absence of halo on specific markings on specific guns is proper or not.

--Dwight

Dwight, thank you for your detailed explaination. It seems that the subjest is very open one, and there are no hard rules. I tried to establish some Halos on my Lugers, but to the untrained eye it is not easy, at least if not one can compare with a very obvious halo. Maybe in time somebody will post good photos of these halos so we can see what they look like.
Anyway, thank you all again for another useful information.
Alf.

Some "halo" photos previously posted on the forums :


http://forum.lugerforum.com/lfupload/halo_copy1.jpg

http://forum.lugerforum.com/lfupload...with_halos.jpg

http://forum.lugerforum.com/lfupload...ug_47927_1.jpg

Dwight,

Regarding your comment of :

" GERMANY export marks are stamped after blue. "

This discussion thread ran over on Jan Still's gun boards. Some folks tended to think that on some AE's, the Germany stamping is done before bluing...both M1900 and M1906 AE were in the discussion...

I think the "Germany" should display halo (i.e. like you said, stamped after bluing...). But maybe both conditions are right and one needs to look for signs of a rework on a gun with a no-halo Germany stamp or look for signs of original finish on such a gun.

Here is that link :

http://luger.gunboards.com/topic.asp?TOPIC_ID=11003

Pete,

Thanks for posting the pics. I recall the gunboards discussion, it was pretty inconclusive. My point to Alfred was to stress that that there are many exceptions to the expected observation of halo--the GERMANY stamp is one of the more striking--and that absence of expected halo, or presence of halo where it is not expected, while requiring a closer look, sometimes is authentically noted.

An interesting observation, which I have seen before and think meaningful, is the halo exhibited by the witness mark on sn 47927.

--Dwight

Dwight,

Suspected that one would stir your blood...;)

Some other halos photos posted over on Jan Still's gun boards in the past :

http://luger.gunboards.com/uploaded/...20arty%201.jpg

http://luger.gunboards.com/uploaded/...rty%20halo.jpg

http://luger.gunboards.com/uploaded/...20arty%202.jpg

http://i165.photobucket.com/albums/u...nk/salter2.jpg


http://i165.photobucket.com/albums/u...nk/salter1.jpg

I have been researching the cause of the halo, there are some really complicated things going on, I have yet to find a simple explanation to post on the board.
For those of you interested in the technical writings do a search for (indentation testing).

Basically you have a flow of metal away from the stamp site; some is directly away from the stamp (downward) and the rest flows upward and outward from the stamp. It is the flow upward that we see as a small bump but itâ??s the outward movement that accounts for the greater area. Much of this occurs on the surface. Here we see surface cracking, under a microscope this would appear as small folds of metal, this makes since as the additional metal must go somewhere. The surface treatment (bluing) will also be cracked as this uprising and folding takes place, this is what we see as a halo.

The candle and pencil tip is a great example; you see exactly what is happening.

Vern

WOW, that is some info, I can see it on my guns now . thanks guys
Alf

Vern,

Can you supply a link?

--Dwight

Two more show & tell photos :


A M1908 Navy Luger...that Joe Salter had for sale some time back :


http://forum.lugerforum.com/lfupload...navy_1139g.jpg

And this next photo is for you, Vern...;)

BUG proofs on a Borchardt pistol that show strong halo...gun was obviously refinished and the mechanic thought to "add" halos back on...looks like with some micro-sand-blasting tool...

(Ron Wood and other guys that know Borchardts have stated in the past that you should never see halo on the BUG proofs on Borchardts...)

Gun was on a previous RIA auction.

http://forum.lugerforum.com/lfupload...roof_halos.jpg

So, shall I take it that if there is no Halos present, it is a reblue?
Al

Alfred, the presence or absence of a halo depends on the model of pistol and the manufacturing process followed at the time. A halo will appear on Imperial Lugers in some places where it does not appear on later Lugers. A careful study of what is expected can be very useful in determining the originality of a finish.

Here is a halo around a Germany export marking on a 1920 alphabet Luger
http://forum.lugerforum.com/lfupload/hwa1920alphap.jpg

[The following two images compare a 1918 Imperial P08 to a reblued 1915 Imperial P08. This example is somewhat extreme but immediately shows the differences:
http://forum.lugerforum.com/lfupload...halo_copy1.jpg

http://forum.lugerforum.com/lfupload...halo_copy1.jpg

A shot of the reciever halo on the 1918. This is a stamping done after the parts were blued.

http://forum.lugerforum.com/lfupload...halo_copy1.jpg

The 1914 Mauser was stamped on top of the barrel prior to polishing and bluing; no halo is present, but it is not expected:

http://forum.lugerforum.com/lfupload/hwa1914_copy1.jpg

Halos may be observed on unblued parts. It is the mechanical polishing that removes the metal distortion that causes a halo.
http://forum.lugerforum.com/lfupload/hwakeyhalo

A picture from one of the technical writings, most just show formulas, they use various terms and not every article uses the same ones. Things like â??Pile-upâ?� â??Radial surface crackingâ?� and Longitudinal surface crackingâ?�.


Vern

Thank you again Heinz and LugerVern. it is good to know as much as possible, which make my hobby more interesting.
Alf

I'd like to clarify my earlier statement concerning (stretched) as apposed to (compressed) surface metal under the halo.
The best way for me to explain my point is to compare the suface metal to the bellows of an accordion. When it is compressed, the pliable material on the top of each fold is stretched, similar to the skin on top of your knuckles when you bend your fingers. Vern noted the terms, radial surface cracking and longitudinal suface cracking. A crack would indicate a separation of metal which was pulled apart. These cracks will only occur at the crest of a bulge or "pile-up". What you end up with is alternating compression and expansion of a very thin layer of metal on the surface. ALL other metal affected by the stamp will be in a compressed state.
Thanks for your indulgence. Now I feel better... unless I'm wrong. :eek:
Mike C.