Author Topic: carburizing (Read 638 times)

AkRvrrat · « **on:** January 30, 2006, 06:55:52 AM »

Does the newer Mausers after lapping and truing require the carburizing process of restrengthing the metal? This pertains to my Higgins Model 50 which some will know is a Belg. FN 98. Just a note of curiousity I have with mine. I am having Stuart Satterlee do my metal work. This chambering .30/338 is having diffuculties in feeding and ejecting is finally being attended to. thanks.

gunnut69 · « **Reply #1 on:** January 31, 2006, 10:38:43 AM »

It is quite difficult to re-carberize a mauser. I know of no one who does this procedure. Still the FN's are alloy steel and don't require the process in any case.. Remember there is likely a difference between re-carberizing and color case hardening..

unclenick · « **Reply #2 on:** January 31, 2006, 12:21:52 PM »

Quote from: AkRvrrat

Do the newer Mausers, after lapping and truing, require the carburizing process of restrengthing the metal?

No. Even on the older case hardened guns, unless the truing takes off a lot of metal you would be in no danger. I've only worked on two or three of these of my own, and they never needed more than a mil or two removed. That's should be safe enough.

As the moderator says, the newer alloy guns will be carbon steels that have received conventional through and through heat treating, so, even though the surface will be just a tad harder than the core, you should still be safe doing a lot of cutting on these.

Color case hardening is a form a carborizing, but it doesn't typically penetrate the surface as far as gas carborizing, which can get down to 50 mils or so, I believe. I seem to recall a tool maker where I once worked usually specified 20-30 mils of skin depth on pieces he sent out for carborizing. The color case method gets more like 5 to 10 mils deep, if I recall correctly? Somebody double-check me on these numbers?

Nick

gunnut69 · « **Reply #3 on:** January 31, 2006, 08:24:33 PM »

I don't know the penetration numbers but most of the color hardening today is done as a finishing process and really has little to do with the hardness of the steel. The hardening process mauser used can actually completely penetrate the side rail of a 98 in the thumbcut area. This can lead to cracking at this point if the action is subjected to a shock such as the action being dropped. This is likely the real reason these cuts are sometimes welded shut on custom rifles. This emulates the commercial actions that mauser produced. The welding entailed in this cosmetic process effectively anneals the siderail of the action, eliminating the cracking problems without endangering the rest of the action's hardening.. As to penetrating the mausers case when lapping in a bolt, I have not encountered this at all. The modern actions are usually the worst when it come to uneven lug bearing..