Heat Treating

J

Jack19

New member
Is it possible to have a receiver heat treated if it's strength is suspect? If so, does anyone know who would do this and how much $$?
 
Send it to the factory. They'll put it on a Rockwell hardness gauge to test it and may only charge you $20 for the testing.

If it's one of those Norinco M-14 clones, I'd send it to Smith Enterprise.
 
Recievers are machined in the heat treated condition. During this process internal stresses may develop. To reheat treat it, it would have to be annealed first. This would releave any internal stresses that may have occurred during the machining of the part in question. It is quite possible that after reheat treating the part that it would not be geometrically the same as it was before it was heat treated.

I would send it to someone who could verify the hardness first, before considering reheating.
 
There are several companies around who re-heat treat rifle receivers. Jerry Kunhausen's book on gunsmithing the Mauser rifles discusses this in detail, and lists one or two of the companies.

Some gunsmithing jobs do affect heat treat, and Kunhausen considers re-heat treating to be a normal, everyday part of these jobs, nothing unusual.

Unfortunately, somebody has my copy, and I can't remember who they were.
 
We must be talking Japanese since Mauser was rebuilt on its site at Oberndorf. OK, send to Smith Enterprise. Must have a good size furnace that allows for gradual controlled cooling. This is generally beyond the capability of the average gunsmith.
 
Would something like soldering rifle sights on a shotgun barrel affect the hardness? Is this a like concern to the question about the receiver?
 
Jack19, the outfit in Kuhnhausen's book is Blanchard Metal Processing (801) 972-5590. George

Romulus, it might but it's not something that you would need to worry about. George
 
Thanks, George. Which is better in your view, in light of the changes to heat treat, for sight installation...soldering or drill-and-tap? How hard is it to hit top dead center accurately? And on a shotgun barrel how important is it really? My 870 barrel has some rotational play, so maybe TDC is still a relative matter...

Thanks again
 
Best strength is obtained with drill and tap, but soft soldered sights usually stay put pretty well, unless you start beating on them fairly hard.

I've attached steel sights to shotgun barrels many times, with excellent results, using the "sweat" method.

I use silver BEARING soft solder. This is NOT real silver solder or braze, it's soft solder with 3% silver content to prevent tarnishing, and to add strength. Since this flows at about 450 degrees, it won't damage the barrel, IF you don't burn the hell out of it. A normal propane torch works well.

The better job of spotting the sights top dead center, the better. This can be "eye balled" fairly well.

How I do it:
I spot the sights by removing the trigger unit and using the bottom flat of the receiver and the flat sides as a leveling guide.

If spotting strictly be eye, you can attach the sights with a drop of Super glue, assemble the gun and check to see if they look really straight.

Once I get the sights positioned, I mark around them with an ordinarly pencil. Using files or (carefully) a flex shaft with a rubber grinding head, I remove all finish from the inside of the pencil marked areas, leaving a fine border just inside the lines, so the bare metal won't show later. Remove the finish from the underside of the sight bases.

Using the soft pencil, I apply a coat of pencil lead to the entire area around the bases. This acts as an "anti-flux" to prevent excess solder from adhering.

For solder, I buy the 3% solder from Wal-Mart or most local hardware stores, and a good liquid flux.

Using the torch, I flux the sights and apply a thin coat of solder, and "massage" it into the metal with an old screwdriver or flattened nail.

Next, I apply a thin coat of solder and flux to the sight area on the barrel. Allow to cool, then apply a THIN coat of flux to the barrel areas, and position the sight base. Apply heat until the solder flows, then carefully press the base down into place and hold until it solidifies. After both bases are in place, scrub the barrel inside ond out, with a toothbrush and hot soapy water to remove the flux.

If you're careful to get a good fitting set of sights, and don't use too much solder or flux. the sights will be plenty strong, and no solder will show.

Another option is to buy a flux-solder paste from Brownell's. This allows you to apply the mix to the parts, position and heat until it flows. This is usually somewhat easier than the "sweating" method above.
 
Dfaris, thanks...I have an 870 barrel with a bead that sits on, well, not exactly a ramp, but some sort of raised pad...can this be sweated off? Or is there a blade sight that coud replace the bead on top of the pad.

Or would the safer alternative be to sell this minty barrel and get one with rifle sights?

Thanks for your input
 
re-heat treatin (Mauser?)

Dear Sir:
I'm sincerely not being dis-respectful of any other advice you have but NEVER try to heat treat any action! With the Mauser we do not know what the analysis is of the steel used. It's supposed to be a good quality medium carbon steel but with not enough "points" of carbon to "heat treat homogeniously".
NO ONE knows for sure how the Germans, or whoever , heat treated these actions! I've heard all kinds of methods from "pack-hardening" to "induction" in just the reciever ring. NO ONE knows for sure.
The process that would have to be followed would be to first idenytify the analysis of the steel. Then carburizing or "case hardening" material needs identified. The in an oven on a rising heat the decalescence temp' is reached. The pyrometer will stand still while the action recieves more heat as the decalecence temp is reached (at which point the steel becomes "non-magnetic). Then it must cook for several hours withdrawn fom the oven and quenched in the proper medium (which NO ONE knows) and the oven then turned off.
Assuming (which makes an ass out of u and me) that it is medium carbon steel and only surfaces are hardened it should be re-heated to roughly 500 to 600 degrees (spring temp for carbon steel) and then allowed to cool. I'm sorry Harry
 
As a metallurgist I have some comments . First when you ask questions please give some information as to what kind of gun, what do you want to achieve etc. That would make things much more simple. A military and most older civilian Mausers , I would NEVER use until I had it heat treated .Wartime guns you never know what was or wasn't done to them. My own Obendorf 1943 M98 was case hardened but it was very spotty . It was sent to a heat treater who worked with these actions on a regular basis.I carefully reviewed their procedure of case hardening and agreed with the process. Have this done only by someone who does it on a regular basis.A soft receiver will set back the lugs and it's no fun to put time and money into a gun only to have to do it all over not to mention the safety aspects.
 
re-METE

Dear METE:
Would you please tell me who does this work on the Mausers? I'd appreciate learning more - I certainly can learn more. Thanks
HARRY
 
Heat Affects Metal. I never heat any guns I work on for any reason, but I do not do long guns so this has been very interesting. Is this one of those surplus guns I see for sale for about $69.95 in the flyers?
 
Romulus

Romulus, if you have paly in the barrel, it means the cut where the ejector holds the barrel is worn. You can have it peened over to tighten up the play in the barrel. The reason I mention this the play you mention can break the ejector.
 
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