The recent posts about heat treating mausers have raised a couple of questions in my mind. The first, is what happens if you have an alloy receiver case hardened? Will it acccept the case? Or will it end up too hard to be useful? I ask because, as I mentioned in an earlier post, my instructor required that his students have every mauser re-heattreated. There was no mention of some being case hardened mild steel and some being alloy that was hardened through. The implication was that they were all case hardened. I wonder what happened to those VZ's in class that were subjected to the case hardening process?

Question 2 is what about the bolts? Were they also alloy vs mild steel like the receivers? With practically all the current VZ's being mismatched you can't be sure where the bolt came from.

I ask because I have one of the Big5 VZ24's that I just lapped the lugs on. Since it had a mismatched bolt it took quite a bit to get the lugs bearing evenly. I did this after truing the recesses. Being the novice I am I didn't think to record the original lug thicknesses and as a result don't know exactly how much I removed. Lesson learned! To be safe, I was going to have this receiver re-treated. I'd hate to have to toss it because I've invested so much time in truing & polishing it. But, now it seems that the VZ�s were alloy and as such won�t require heat treating.

The more I think I learn the more confused I get!!!

Z1R,

I have also had concerns re: bolt use. Is it safe to use an early bolt with a late receiver? What about a late K-98 bolt with an early DWM receiver? I have both, in custom rifles. Not sure about the answer or where to look though.

Todd

I'm hoping Mr Burgess jumps in. His ideas and experience is different from mine.

One thing for sure though.....If a lawyer ask why you had it heat-treated by anybody but the guy that made it to begin with, it's a tough question to answer and keep your butt covered.

Tom, tell us about this gas carborizing thing. Is that Blanchard that's doing it? I have a ZKW that's peanut butter soft.

Jack,

There is an outfit here in the cities that does the gas carburizing thing. I have had them do a number of receivers for me. Metal Treaters, Inc. I will get you the phone number if you want.

Jack, Todd, & ,

My hornet midget ain't much better. When I get off the dime and make a Siamese style Rimmed ctg magazine box for it ,it will get carburised. The clip works just fine and is exceptionally well made, I just like the idea of a Midget Mauser that looks like big brother.
I am well aware of members of the shark family, Genus Shonikeridae, always circling, always..... This is why no bunker busters launched from this direction. Only time this ever got to the deposition stage the protagonist to be drove up in a beautifully restored Cad 6 wheeler, complete with latest Goodyear tires requiring late style rims. I for an analogy mentioned how I had missed out on a Packard Phaeton 6 wheeler,(pause) but of course for safety reasons not just for myself but for my fellow motorists I would go to the trouble of getting the most modern technology tires even though that would require new wheels and the chromed covers and brackets for the side saddle spares. Didn't need to mention the Cad. "My guy" rolled his eyes toward the ceiling at that pronouncement and it didn't make it to court for a solution. Yeah, outhouse luck, but a fair comparison.

In '49 or '50 I got a nicely made Mauser in 7.65 caliber, complete with 1/2 rnd. 1/2 oct barrel, Hinged F.P. mag, and tastefully engraved by some engraver who liked his workpiece to be no harder than the cheese on a bagel. Owner wanted to make it into an '06 to fix the headspace. Bob Owen thought I ought to try a large outfit in Cleveland to get the receiver fixed up. As it turned out they had a couple of escapees from the communist takeover of Czechoslovakia---Brno to be exact, and Zbrojovka Brno,A.S. precisely. Subsequent Phone calls to these 2 "Diploma Engineers" provided me with information overload, but a general sense of what was required for British cordite and American propellants and why continental Europeans heat treated as they did and what ought be done for our powders. The receiver came back with shrunken headspace and I did my first lug lapping and left it in 7.65.

Jack, E- Mail me for specifics on Gas carburising. You don't get orange peel or warp with the gas. Posting here could just add to the confusion.

And yet more questions...

I've been doing a bit of research, and managed to fill in some of my ignorance, but not all of it. Also managed to gin up some new questions, so here goes:

1) Why aren't actions made like they used to be, i.e. case hardened, low carbon steel? Is it strictly a matter of economics: pack or gas carburizing is just too expensive for mass produced, factory rifles? If that's the case, then why aren't custom actions (which presumably aren't governed by the same factory production economics) made the old way? I may just be ignorant and not know of the custom actions that are made the old way, but all the ones I know of seem to be PH Stainless, 416 Stainless, or 4140, and they're through hardened. It seems that at least some of the 'smiths here don't think that is the best way to do things.

2) In reading Mr. Burgess on military Mauser metallurgy and perfect action daydreaming, it looks like the Mausers are pretty close to the carburized 4130 that Burgess dreams of. However, in reading one steel vendor's data sheet on 4130, they specifically state that 4130 is not recommended for carburizing. Are they just full of it, or is there something special about rifle actions that makes this general recommendation inapplicable?

3) Are actions ever nitrided? It looks like 4140 is a good candidate for nitride case hardening, so what's to prevent one from taking a modern 4140 custom action that has been through hardened, polishing and lapping it to near perfection, then having it nitrided for an even harder surface, and finally doing any last lapping and touch up before applying the metal finish? Will nitriding prevent rust bluing or make the action less than acceptable in some other fashion? Or is nitriding just too expensive? Has anybody ever tried anything even more extreme like building an action from Nitralloy and then nitride case hardening to a very hard surface over a soft core?

Lot 'o questions. Anybody who knows a lot more than I do find them interesting enough to answer?

[ 04-04-2003, 10:50: Message edited by: InfoSponge ]

z1r

This has been discussed here befor. Check out this post.It's a good one. http://www.serveroptions.com/ubb/Forum5/HTML/002176.html

For what it's worth this is my policy on re heat-treat.
All actions are individually judged for their intended use.
Any action that has had any of the following will be re heat-treated.
Surface ground,depending on original condition,
Any welding,
Lug setback,
Lapping of lugs more than .002,
Re machining to correct any of the critical dimensions.
These are the basic guidelines that I use to judge whether the action is re heat-treated or not. ALSO NOTE,in most cases a untreated receiver is safer than one that has been incorrectly re heat-treated.

James

This all really makes the M1999 actions look so much more appealing than they already are.

I just spoke to Blanchard who said that even the so-called alloy mausers can be cased. If that's so, and you really do feel that the receiver needs to be retreated then it sounds like it doesn't so much matter as long as the treater knows what they are doing. That I guess is the real key, a reputible, knowledgable heat treater.

Thank's to all for helping to muddy the waters.

Z1r,
Here's a shot of a 1909 Arg. that has been casehardened in charcoal, just to give an idea of what it looks like.

Kboom,

That's beautiful! Who did that job?

Todd

Todd,
I did this at a few years ago at a summer seminar at Trinidad College.

Pack carburizing is ok for individual actions but gas lends itself better to mass production. Nitriding is usually combined with carburizing ( carbonitriding) giving a very hard but thinner case. You will find this in guns like the Glock with the german trade name Tenifer. Alloys containing up to about .30% carbon are case hardened.When I was in gunsmithing school the recommendation was to case harden at least the military mausers.My own mauser was spotty some hard and some soft areas.As a metallurgist I was very interested in exactly how they did it.Could they do it so as not to get it too hard etc. I'm sorry I can't remember the details but their procedure was very satisfactory to me.

Had enough information to post when the system developed constipation and it required over an hour just to get to the forum. Never could get to the posting site.

I believe the alloy versus "plain low carbon steel" mix up occurred due to the expense required to get a test made on the steel. In the old spectrographic method of analysis involving burning the sample in an arc or in a hydrogen flame the wave bands for iron and that of manganese (color) were nearly indistinguishable. If you suspected manganese beyond the normal ammount found in most all steel because it was used as a de-oxidiser in smelting and mixing, therefor, the quantity had to be determined by quantitive analysis, a rather expensive undertaking. While still in high school I wondered if what gun pundits of the 1920's and '30's said was correct and brought a bolt handle to the head Chemistry professor of the parent university for analysis, He mentioned that this sample (from WW I ) seemed to have extra manganese in it because of the Iron "show" appearance. I couldn't see it but what did I know ? However, the guy who was welding a different handle onto the bolt body for a gunsmith had said the bolt had a bunch of manganese in it and like a dumb kid I mentioned this. 5 sample pieces, much weighing, disolving in acids, heating the liquids, and finally applying a strange organic acid to some precipitate and I had a measurable ammount to weigh and then it was moles and molals and finally a percent. I vowed never to get THAT involved in Chemistry again. In the mid 1950's and later I negotiated with gun-nut types employed at firms having labs containing Nuclear- Mass and other types of analytic machinery to have my samples "lunch-boxed in and out". The experience there was that among metalurgists the purists called the metal an alloy and the dirt under their fingernail types maintained that the manganese was used to off set extra sulphur for smoother machining and longer cutter life + a make-up for the sulphur retarding the carburising process and causing "hot-shorts" cracking in forging as well as providing more lee way in forging temperatures and a lower carburising temperature. I toast that conclusion. Agreement,
Mete and Infosponge??

My own conclusion, a carburising procedure properly executed, is possible on any mauser showing the need made from 1898 through 1945 by firms or arsenals of repute .

I'll add to this, probably in a new thread later.

You will find an interesting discussion of gun steels from 1903 to 1947 in Hatchers Notebook. As for manganese, often free machining grades are used which mean higher manganese and sulphur. I don't think that analysis was a major problem. There are many variable s to cosider; technology available , costs properties. It is interesting to note that some of the old receivers were pack carburized which would not be done today.

Infosponge.
The Rem (Springfield type) 03-A3 receivers and some bolts when made from AISI 8625 steel, as an experiment had a heat treatment which also provided a nitrided surface. These parkerised quite nicely in the familiar gray green color. Sand blasted then polished and immersion blued they achieved a wondrous irredescent green. I know of no one who Rust blued any because of the time and care involved in producing that finish, but it ought to have required at least double the coatings and would most likely have produced reds as well as greens.
To further speed production and since the 03A3 was not intended to be used outside continental U.S., parkerising process was abandoned in favor of the conveyor link chain with hooks dragging the parts through boiling vats of immersion bluing salt solution. War Dept. didn't like the green color either. No abrasive or acid etching was required for bluing as a preparatory step.
98 MAUSERS
What trace elements might show up in a given lot of steel determined how much manganese would be used to balance FOR THE DESIRED RESULT. Extra copper in small ammounts can retard carbon absorbtion, more manganese can offset it, Max ammounts of sulphur can result in Hot shorts, a tendancy to crack in rolling and forging the steel billets. More manganese can offset that, If all the combinations indicated a need to cook the receiver longer to achieve the desired depth of case they simply did so. Once you have the limits in all directions you have a formula for ease of manufacture. That is all right by me. My preference is for something that simply stretches without turning to fragments in a worst case scenario catastrophic blow up. Properly executed carburizing does that. The '98 receiver was designed to be machined using a minimum of circular form cutters. About 90% of the exterior contour was rotary milled . The part was rotated on a turning axis under a fixed cutter assembly. The chips were very sharp needles which cluttered up the holding fixture. Sulphur and manganese altered the chip form just that ammount requiring the least ammount of cleaning for the next work piece. This action design- Systeme 98- (how about that?) was rather thoroughly worked out. Prior models used form ( shape cutting) cutters. These required skilled toolmakers to produce and required skilled tool sharpening to maintain the form .... and a different steel recipe for the best form cutting. Though not by much.
Design departures which eliminate the internal "C" ring require more careful selection of steel. When F.N.s let go that have the slotted internal "C" ring they usually peel the top off,sometimes all the way back to the bolt stop slot. Broaching the receiver all the way through in one pass involves about 1/6 th time required for a reciprocating rifling head type cutter at say 50 strokes per minute, even though the Extractor side has to be opened up for the extractor using the reciprocating tool method. An alloy type steel is more conducive to Broaching and can be heat treated to stay in one piece at a point where the Manganese steel is stretching. What turns my crank is the fact that it is still stretching albeit grossly when the alloy has become a hand grenade 5 inches from your nose.

I can not think of any action designed with negligence or a cavalier attitude regarding operator stupidity. With a medium carbon alloy you will get a top limit beyond which the steel refuses to stay in one piece. The full "C" ring mauser will be stretched beyond redemption.

By "alloy" steel I refer to medium carbon- 37 to 50 points, and additives of Nickel,or Vanadium , or Chrome, or Molybdenum separately or in combination.

Before WW II there were steels made in the U. S. , called "Machinery steel" and these contained carbon and manganese in similar ammounts
to the mauser chemistry in the lower carbon version. Today we still have a heavily cold worked manganese bearing steel called "Stress-Proof" and another one called fatigue proof which have from.37 to .44 carbon. Fatigue proof is not heavily cold worked and is very similar to what was once called " Ordnance steel".
No, This was not what I had planned for additional, Later.

Heh, heh... I'm having a tough time matching up questions and answers, but I don't mind, Thomas. What you're providing is great stuff. Thank you.