Ok here is something I would like to understand better. My understanding is that the original heat treatment of the Mauser's was to surface harden the action with perhaps, selective deeper hardening of specific areas such as the bolt lugs. I understand that the surface hardening was to "slick" the action up for better function or cycling as well as to provide strength to high pressure areas. The interior of the actions, the steel core, were left soft so as to give in case of some type of failure of cartridge or barrel blockage etc. This soft interior allowed the action to swell or give while at the same time protecting the shooter. I get this and it makes sense to me.

What I have never heard the reheat treat proponents speak of is the importance of maintaining this soft inner core and the safety margin it provides. It seems to me that for some reason this reheat treatment destroys this soft inner core. I mean if not, why not simply work the action over then spend the 80 bucks to reheat treat it?

So do the Pro reheat treat people simply feel the hard surface soft interior is the wrong way to go about it?

Why can't one simply anneal the entire action and then duplicate the original Mauser shop's heat treatment? It seems to me that the lapping and truing one does in customizing an action could remove or seriously weaken the thin surface of hardened steel.

Howard

I have some literature here that John Westrum sent me a long time ago. I believe he has since passed away.

John was a Gunsmith in Iowa. His main business was reworking mauser actions.

In his literature he speaks about mauser heat treating.

He used a Cyanide salt bath treatment. (I am not sure that method is now available)

John's reasoning for using Cyanide Salt Bath goes to your question. He did not want the interior of the action to lose its so called "softness" so that the action became brittle. Rather, his goal was to add carbon to the outside of the receiver. He mentioned that he had several mauser receivers tested for carbon content and there wasn't much there. Carbon is one of the things that helps to make steel hard.

quote:

Originally posted by Howard:
Ok here is something I would like to understand better. My understanding is that the original heat treatment of the Mauser's was to surface harden the action with perhaps, selective deeper hardening of specific areas such as the bolt lugs. I understand that the surface hardening was to "slick" the action up for better function or cycling as well as to provide strength to high pressure areas. The interior of the actions, the steel core, were left soft so as to give in case of some type of failure of cartridge or barrel blockage etc. This soft interior allowed the action to swell or give while at the same time protecting the shooter. I get this and it makes sense to me.

What I have never heard the reheat treat proponents speak of is the importance of maintaining this soft inner core and the safety margin it provides. It seems to me that for some reason this reheat treatment destroys this soft inner core. I mean if not, why not simply work the action over then spend the 80 bucks to reheat treat it?

So do the Pro reheat treat people simply feel the hard surface soft interior is the wrong way to go about it?

Why can't one simply anneal the entire action and then duplicate the original Mauser shop's heat treatment? It seems to me that the lapping and truing one does in customizing an action could remove or seriously weaken the thin surface of hardened steel.

I believe that is what outfits like Pacmet do. They harden them to a certain depth.

Jason

Ladies and Gentlemen:

From my research, it appears that the "soft" inner core of the 1898 Mauser has plenty of tensile strength for its application. Also, the core steel of the receiver and bolt are different.

Additionally, the core samples that I saw were assayed with a low carbon and a higher manganese content, so that the heat treatment could not "overharden" the core when the high carbon case was applied.

So, if you re-case the receiver too deeply, you have defeated the purpose of the amply strong core that could also take shock without shattering.

Recently, I have learned that in one metallurgist's experience, full annealing would not remove enough of the surface carbon to accurately re-case the Mauser bolt and receiver, making re-casing the action questionable at best.

As a side note, I have an "new" 1908 Brazilian of DWM manufacture with all matching serial numbers. There is a definite indentation from the upper split lug in the lug recess of the receiver. It appears that this occurred during the proofing of the rifle.

The indentation is only about .001" as far as I can tell.

I have some other "new" 1908 Brazilians of DWM and Oberndorf manufacture that do not show this indentation.

Bolt upset into the softer receiver?

Was the proof load too hot, and it caused the upset for full lug contact? Interestingly, this receiver and bolt were both the hardest ones of the lot, when I had them Rockwelled on the "C" scale about 10 years ago.

I'm going to barrel it up, and pull it apart after 1000 rounds to see.

Sincerely,

Chris Bemis

quote:

Originally posted by Howard:

Why can't one simply anneal the entire action and then duplicate the original Mauser shop's heat treatment? It seems to me that the lapping and truing one does in customizing an action could remove or seriously weaken the thin surface of hardened steel.

Case hardening can be done to just about any depth you want up to about .080" deep. Most action are case hardened to .030" or a bit deeper Correct me if I'm wrong on that one but they are nearly never less then .030" deep.
The point I'm getting at here is on a newly heat treated case hardened action there is no way lapping the action is going to remove enough of the case to be a problem. Lapping as a process in itself only removes .001" to .002" over all at the maximum unless some poor schmuck just ran away with things. On an action you are not removing nearly that much unless something is seriously wrong with the fit. and a sloppy fit on a glass smooth piece of steel may often feel worse then a good fit on a not so smooth piece of steel as the sloop can cause a bind no matter how smooth the fit. lapping is a very gentle way to smooth out an action kind of like rubbing down a bolt with 1000 grit paper. It will make it shine but it won't remove a lot of material

What kcstott said about lapping and case depth.

I don't believe anyone here has any concern about the tensile strength of the Mauser action. It's not the safety of the action that's the issue here, it's the action's resistance to permanent deformation in the form of bolt lug setback.

Permanent deformation. Think about it, the steel has actually failed in service!

Yes, the Mausers are case-hardened, as are the Springfield 1903s and the Japanese military bolt actions. I notice that no one here, repeat no one here, has cited any instance whatever of lug setback in either the 1903 or either of the Japs, while lug setback in many Mausers appears to be not uncommon to say the least.

To me that's pretty hard evidence that the Mausers are 'softer' than the 1903s and Japs. To me it indicates a shallower case or possibly a much-less-tough core, IOW some condition that would allow the Mauser's hard outer shell to deform back into the softer core. And this softer Mauser condition is obviously not required for strength, just compare the PROVEN GREATER strength of the Japs and double-heat-treat 1903s against the Mausers: absolutely no comparison whatever!

I, for one, believe that the obviously-softer Mauser case-hardening can be noticeably improved by re-heat-treating. And P.O.Ackley also preached this.
Regards, Joe

Ho Boy... I love it.

Just like the (not all that good) old days.

Here we have it folks.

Emblematic of most everything you'll read on AR.

Jeff, the consummate amateur, king of the bogus stock makers, moderator, full of sound and fury, arguing with...

Duane Wiebe.

Guild member, creator of rifles of surpassing beauty and utility, master of wood and steel, accomplished riflesmith in every sense of the word.

Jeff, I admire your chutzpah.

Many would be in awe of Duane and his experience and accomplishments.

But you're not afraid to call him wrong.

Reminds me of the story of the definition of chutzpah:

It was the teenager who killed both his parents, and asked the judge for mercy on the grounds that he was an orphan.

flaco

Where do we send the tickets?

Bon Voyage!

[quote]
" What a nasty surprise. I pulled the barrel (270) off a 1909 Arg action, planning to grind down the charger hump, reshape the rear tang a little, and reblue it. This is the action I just got the PME 2 pos safety set up on, new Leupold bases / rings, stock in the works, etc.

Looking it over, I thought 'my, that upper lug recess looks funny' -- actually it looks like the Steyr that Jack has posted pics of. I grabbed a small punch, and sure enough you can feel a step off when you run it over the front of the lug recess.

I will try to post pics if I can borrow a digital cam; the real bummer is, this was a DWM, in almost perfect shape, never fired with hot loads, barrel installed properly by a smith who knows how. I can't figure out why it happened.

Todd." [endquote]

Tom Burgess reply ;....

[quote] " For Todd, Jack, et all ref lug seat pocketing in
various mausers. DWM '09's; After rockwell, DIN,and other hardness testing of between 450 and 500of these animals (category-09's)which included
cadaver research, (of some few that were beyond salvage), disecting and acid etch to determine carburising depth, I came to the conclusion that without exception they would all need additional depth of "case". Where it counts the depth rarely exceeds .007". Hardness? average about Rc 9.
Some were in the minus numbers, and rarely- perhaps 2 or 3 made it all the way up to Rockwell C 18.
The Argentines wanted to shoot up several 10's of millions of rounds of ammo made for the '91.
The bottom liners at DWM (Loewe) saved Marks by cooking the receivers and bolts in 10-12 minutes
less time. All that was determined to be needed for the '09 and the '91 ammo. Austria provided spitzer ammo about 200 FPS faster for the Schwarselose Machine gun, Troops and Jr ballons being the same the world over this ammo naturally got fired in the '09 rifles and carbines with a similar result to Todd's.
.... Remember that you are not dealing with a static load during the "instant" of firing. It is, rather
DYNAMIC- very much so with U.S. style propellants
as opposed to the early 1900's flake powders of the Germans. The .270 Todd can have as many as 5 "benches" in the so called pressure curve starting at about 93K PSI levelling of in the low 40's yet read a uniform load to load 58K in the old copper crusher method of pressure testing..." [endQUOTE]

quote:

Originally posted by flaco:
Jeff, I admire your chutzpah.

Many would be in awe of Duane and his experience and accomplishments.

But you're not afraid to call him wrong.
!

Wrong is still wrong, regardless of the source of the error. We should always remember:

You can lead a horse to water but you can't make him drink.
You can lead a man to logic but you can't make him think.
Regards, Joe