Questions for firearm experts/engineers: late model Mauser 98K, safe to fire?

[Johan762]

Hello everybody:

Are the Mausers produced in late 1944 and early 1945 safe to fire? I have a sporterized (more like butchered stocked) 1945 Mauser 98K that I used to shoot occasionaly. I have doubts about its metallurgy (after all it was made in a time when Germany was losing the war rapidly) and stopped shooting it years ago. I got myself a 98K manufactured in 1939 as a shooter, instead.

The reason for my doubt over the rifle's metallurgy is because when I was in school, I took a metallurgical specimen (from the rifle's chamber)out of another late production Mauser (1944) that was really worn out. Upon the micrographs' examinations, it was noticed that the microstructure of the rifle's steel was non uniformed, to say at the least. Instead of a microstructure consisting of 100% tempered martensite, a few large areas ("spots")of fine pearlite was observed. What caused these areas of such extreme microstructural discontinuities to exist? How can the rifle's steel had so many "spots" with such distinct different hardenability? Was it possible for a very severe elemental microsegregation to occur during the forging of the barrel, thus giving the metal areas/spots with extremely diferent hardenability?

Now folks, I am not talking about trying to make a full martensite out of 1" diameter steel, here. A Mauser's chamber wall is much less than 1" thick. Even with a steel with rather low alloying elements (such as Cr, Mn, and V), I should be able to expect the rifle's chamber wall to consist of 100% martensite after quenching (thus 100% tempered martensite after the tempering process). So what's up, here? I remember taking the hardenability test (in Rockwell C scale), but I do not remember the exact value (somewhere in the middle 30). I remember, however, when using a chamber pressure of 75,000 psi (max for 8mm, isn't it?)and utilizing the thick walled cylinder formula, my calculation showed that the rifle's chamber ought to comfortably withstand the stress it is subjected to. I am, however, worried that the steel's microstructural discontinuities would have a detrimental effect on the steel's fatigue endurance. And after being shot for more than 50 years, there may be a good chance for the rifle to blow up on my face. Remember, fatigue failures always occur without warning and always catastrophic in nature.

So what do you all think? Any advice/opinion would be appreciated.

Johannes

P.S.
I was too stupid to perform chemical analysis on the steel, so I can't even guess what type of steel it was (in US equivalence).

 

[Snail Male]

The Germans believed that forcing steel under the hammer compressed the molecular structure of the metal; thus making it stronger. This hammer type forging is probably the explanation (but I'm not certain) for the disturbed grain structure you saw in your sample of Mauser steel.

My father worked in steel mill that made 88mm gun barrel blanks, and these blanks where fall hammered (by Russian slave laborers) into the rough outline of a gun barrel. Then the barrel blanks where shipped to another factory for finishing.

I read an article on Mauser rifles, and the article stated that the recievers of these rifles are very hard on the outside and fairly soft on the inside (like a Glock pistol slide). This type of hardening makes it *virtually* impossible to blow up Mauser rifle. In event of a catastrophic overload a Mauser's bolt lugs *should* set back, and if the pressure is great enough the bolt will weld shut in the reciever and melt--rather than blow up. It seems unlikely that the heat treat of your late war Mauser could be bad, however I don't blame for no wanting to shoot the thing.

 

[Art Eatman]

From my reading about the last days of production in Nazi Germany, quality problems were in machining, fit and finish. Most warnings I read as to rifles had to do with headspace. And, of course, the noted "glass-slick" smoothness of the actions was not as likely as 1943 and earlier.

If it hasn't already blown up, it probably won't do so in the future.

All in all, however, since you've replaced the rifle with one even more likely to be safe, you might as well turn the 1945-model into a lamp post. A $100 gun ain't worth a major medical bill, right?

FWIW, Art

[This message has been edited by Art Eatman (edited March 29, 2000).]

 

[Herodotus]

I confess to avoiding these rifles because of their reputation and to having no practical experience with them. That being the the case, I can only quote from authority: Jerry Kuhnhausen in "The Mauser Bolt action":
"M98K's were made in various plants in Germany and occupied Europe during world War II. With the combined effects of increased bombing raids and partisan and slave labor sabotage, M98K quality contol slipped in 1942 and grew worse into 1943. Some M98K receiveres, bolts, barrels and action parts made in 1942 and thereafter are questionable, and in some cases, even potentially unsafe. M98K parts made after 1942, including bolts and receivers, are generally of much lower quality and are frequently found dimensionally off-tolerance and with skipped machining steps. In other instances, some components appear to have been made from various substituted steels. Heat treatments vary considerably as well. Late M98k bolts and receivers have been found that were extremely soft, or at the opposite extreme, over carburized to the extent that they were brittle."
He goes on to caution against lug surface setback, which is difficult to note in a barreld gun. (A warning sign of this would be stiff bolt uplift after firing a around.)
He notes seeing bolts without rib guides and lacking gass vent ports.
He advises looking for acceptance marks on late M98K parts: little eagle and swastika over a number on all critical parts. Lack of these could indicate rejected parts that were used anyway.
I do remember reading that FN Herstal (Belgian) employees made a real point of sabotaging reciever and bolt heat treatments during the war. Appartently, they could get away with this more easily than other, more obvious types of sabotage.They were trying to overheat them so that they would be britlle and fail after a short service life. I would not want to shoot any FN made rifle of this period because these people were clever and fully understood what they were doing.
I also remember see Dr. Ambrose, the historian who did GI interviews for his popular series on the American GI in the European campaign, say that he thought sabotage by slave laborers was a very real thing in late WWII, but almost impossible to document in a satisfactory way. He noted that a number of American veterans reported being saved because a German shell failed to explode. The shell would come in with lots of noise but no explosion. The shell would be found impacted into the ground near their foxhole. He had found no accounts of American shells failing to explode in his interviews with German veterans.
I don't think anybody will ever be able to unravel what went on in German controled arms plants all over Europe during WWI. My own personal reaction is to not shoot these weapons, although I know that others do and that many or most of these rifles are sevicable.
Also, I do not know of any verifiable account of these rifles failing catastrophically. Perhaps the basic Paul Mauser principle of having softer, very strong and elastic interior steel covered by thin hard outer layer produced by heat treatment was such a basically sound principle of safe design that it was able to largely overcome sabotage, incompetance and shortage of the proper materials. If that is so, it is truely a wonder.

 

[Johan762]

Gentlemen:

Ask and ye shall receive! This board is trully wonderful! Thank you for your helpfull, very interesting, and knowledgeable replies. You gentlemen are really rich in facts that were gained from literatures and informations from trusted family members. And thank you for having the patience to read my long post.

Snail Mail: your father is absolutely correct about the process. Cold working (cold forging) will harden a metal due to grain size reduction. By reducing grain size, you tend to impede the motion of the dislocations (by means various mechanisms that I won't discuss here). I assume, however, that they must do some stress relieving after the cold forging process (stress the word ASSUME, here).

Art Eatman: I think you're absolutely correct. A $100 ($75, actually) rifle doesn't worth a major medical bill.

Herodotus: I am a product of the public school education, so pardon my ignorance: wasn't Herodotus a Greek historian? With your deep knowledge in Mauser 98K's history, that name trully befits you. My hat's off to you sir!

Again, gentlemen, thank you for your valuable inputs.

Johannes