Expert smiths - can this be done?

[rookhawk]

For originality's sake:

Could you micro-tig a rifle chamber full and ream the chamber again to correct excessive headspace?

A.) no can't set back the barrel

B.) a new barrel would be impossible without destroying the gun's value

C.) ignore cost concerns for purpose of discussion

D.) chamber sleeve is not appropriate for a variety of reasons

It seems to me that this would be the "proper" way to address a collector's item rifle but I don't know the metallurgy nor whether it has been attempted. Would love to hear someone in the know discuss this.

 

[rookhawk]

@Von Gruff @Red Leg @PHOENIX PHIL @spike.t @Ray B and others, thoughts? Is the metallurgy impossible for a bond? Would it not be proper hardness?

 

[nztimb]

I rely on the gunsmith to do the metalwork so have to answer this question with what my initial reaction to seeing it bought on.. Just thinking through the proposition though and depending on whether you needed the full chamber depth done, it is something that I would be wary of because ot the difficulty welding cleanly right round the chamber and down to the depth needed. With that much heat there is the heat treat concern as well so all in all I dont think I would ask a GS to do this.

 

[spike.t]

sorry that getting way way beyond what i know, but what Von Gruff says sounds logical

 

[PHOENIX PHIL]

@rookhawk, sorry I haven't a clue. I think you need to call an expert on gunsmithing in regards to this one.

 

[Red Leg]

Like you, I would be the one asking.

 

[rookhawk]

Reason I asked if you're curious: over the years I've seen many lovely take down rifles offered for sale with excessive headspace. If they could be made serviceable for say $1000-$1500 by micro-tig welding the end of the chamber and then cleaning up with a reamer it would take $4000 wall hangers and make them $10,000+ working guns. I've seen some horrifying alternatives like re-chambering to bigger cartridges, rebarrelling to which point the take down never worked right again and even partial chamber sleeves and full length sleeves. All irreversible destructions of nice guns.

If this sort of work could be done I would give these guns additional consideration when I see them. Such a nice 6.5x54MS by George Gibbs was the last one I saw needing such rehabilitation.

 

[nztimb]

So you are only talking about building up the headspace which is a different story and may not be necessary at all, as, if the chamber is okay except for the headspace then it is a simple thing to neck up the brass and resize to the longer chamber. Maybe have a custom die made if that is required which is all the cost that should be involved.
When I built my 6.5 Grendel-Max it had the standard reamer specs but with the shoulder mooved forward by .05 so greatly increasing the headspace. I necked the grendel brass up to 30 cal then necked back down to 6.5 but left it .006 longer for a light crush fit for the fireforming and have used it for a few years now with great success. I was even able to use the standard die by epoxying a .05 spacer into the base of the shell holder so the custom reamer with longer base to shoulder length, tighter throat and longer leade was the only extra cost involved.

 

[rookhawk]

@Von Gruff from a purist perspective the issues would be:

1.) gun is out of proof

2.) you're making wildcats that don't match the proofs

3.) fireforming the brass may cause undue web thinning to the brass on first load.

That being said, yes, your path is usually viable. I just wondered if my approach would be possible as it would bring it back into proof in the best way to conserve a lovely old gun. I hate when irreversible modifications happen to vintage guns so I thought micro-tig may be the new way forward.

 

[stug]

Can you come at it from the other end and build up the bolt face? How much excessive head space are you talking about?

 

[rookhawk]

Can you come at it from the other end and build up the bolt face? How much excessive head space are you talking about?

It's theoretical as I don't have a gun with the issue but typically headspace issues are what, .010" or so to correct?

I also wondered whether bolt could be built up but I had a smith tell me never. Not sure why?

These types of guns go cheap in Europe but they must be sold to a gunsmith as no out of proof gun can be retailed. Thus it makes for a complicated purchase.

 

[35bore]

Best to speak to a metalergist. If something like this could be done, there would have to be a lot of attention to the hardness of the metal at the end of the project.

That or contact the manufacturer to see if they can "re-fit" it for a reasonable cost.

 

[Ray B]

An answer may lay in the technology of the time when the old guns were made. Thirty years ago I knew a blacksmith that repaired just about anything made of iron or steel. If the barrel could be separated from the rest of the gun it may be possible to forge an insert into the chamber so that it bonded with the barrel without getting the barrel so hot as to alter its strength. Then the barrel could be spun on a cutter to trim away unwanted metal, leaving a barrel that met new specs. Likely it would need to be reblued. Unfortunately, both the blacksmith and the barrelmaker that I knew have both passed away so I don't have any connections to anyone in the trade.

 

[375 Ruger Fan]

I will offer my limited expertise..........I'm not a gunsmith, nor did I sleep at a Holiday Inn Express last night...............

 

[375 Ruger Fan]

 

[Graham Hunter]

Gunsmith for over 40 years. No to welding internally as you could never re ream the chamber correctly as well as the heat will change the temper. To many liability issues as well. With headspace only .010 only you could size the brass to eliminate that no problem. From .030 t0 .050 you could still size the brass but will thin the web with repeated firings and will separate. If you are willing to throw your brass out after 2-3 firings you would be good. Head space after that requires setback or replacement.

 

[Longwalker]

I have a very nice old Heym BBF in .222/16 ga that has a long chamber in the .222 barrel. The headspace is about 0.012" which is over max. So I just prepared a hundred cases filled with a small charge of fast pistol powder topped off with cream of wheat. Rifle shoots accurately, and the cases last OK as long as I don't full length resize.

 

[Ray B]

I'm not sure what the reason for the excessive headspace is: setback of the bolt, stretching of the action or other causes, if the only problem is that the headspace is more than desired, but the action is otherwise tight it would be similar to a Remington Model 30S that a friend of mine has. It is chambered for 257R and when factory cases are fired in it they get a lot of stretch at the web. His solution is to buy 7x57mm cases. Run them through a 257R die, but leaving a "bump" at the juncture of the neck and shoulder. the loaded cartridge is held back tight against the boltface when it is fired. The shoulder fills out against the chamber and the cartridges are now a perfect fit for the rifle. They wouldn't work in a standard SAAMI chamber but they work great in his rifle.

 

[rookhawk]

@Ray B

Here's the story: You cannot sell a gun that is "out of proof" in Europe as defined by the London/Birmingham proof house and/or CIP. With some regularity I see take down rifles that are about to be trashed in the EU/UK because they are out of proof. I'll give you a perfect example, one of hundreds: .318 Accelerated Express was invented in 1910. It was certified and approved by CIP in 1984. That means for 74 years people made them any which way they wanted to within reason using old reamers and "good enough" tests using kynoch ammo. But now that gun or many, many other guns in europe fails a go-no-go headspace gauge and is deemed "out of proof" and cannot be sold to the public. This is even if the gun really hasn't been worn down much at all but was made with a loose chamber.

IF I could get them micro-tigged and reamed to clean up the chamber in the EU or UK the gun would no longer be out of specification. Unfortunately, I'd have to have the gun purchased and sent directly to a gunsmith as I cannot take possession of an out of proof gun as a civilian.

You see, with regular rifles everyone knows to just set back the barrel so the problem is worked out and thus are no deals on regular bolt rifles. But on out of proof take down guns that cannot have the barrels set back easily? Yeah, I've seen some deals over the past two years. Rural British gun trade doesn't want to mess with them and would be happy to get money and send them to another gunsmith to deal with.

So that's the story. I see deals to be had out there if they can be put back in proof and then tested by the London/Birmingham proof house before import to the USA.

 

[ChrisG]

I will come in here from an engineering standpoint... practically speaking, the issue is that even a well done TIG joint or micro TIG joint is a non-homogenous casting. Those who said above that it will destroy the heat treatment are right. To what extent would be based heavily on the original alloy. It may not make one bit of difference. But for me there would be a more pressing concern of voids and irregularities in the TIG fill-in. There are 3D printers available which may be able to fill in the chamber using a laser sinter process with finely powdered metal blown into a sintering laser and fuzing them to the surface. The only other way I could see doing it would be to hog out a larger area than the chamber itself on a lathe, mostly to provide a larger bonding area, then plug the bore with a well fitted piece of grphite that would extend through the chamber and out the back of the barrel (as a centerline cast in a mold.) Then heat up the barrel and pour molten steel into the breech in an inert gas environment. This would fill the whole chamber in but stop just short of the throat. Very VERY involved but it would create a fairly homogenouse steel fill that could then be trued up, machined and re-reamed. There are facilities that could likely do something like this but I don't know if they would take on a project like this. A good borax flux would likely ensure a good bond and then the whole thing would have to be heat treated back to it's factory spec and reblued. All of which would probably destroy any original value the gun had. Even a tig weld may heat it enough to destroy the bluing.