Hello Folks

Could someone point me to a resource or describe (at a basic, non detailed level) the steps and machinery required in machining a new 98 bolt body (with weld on handle) from bar stock ??

Thanks

There's no real way to explain it with out getting a wee bit technical and long winded too.

You need a lathe, a milling machine, an EDM or a special made Broach, a place to send it for heat treat, a good selection of cutters and a machinist that knows what the end result needs to be.

Machines should be fully tooled.

You might wish to direct your inquiry by PM to Timan, who posts on this site. He has made a few of them in his shop.

Here are a couple of photos of some of Timan's bolt handles during the manufacturing process.

The lathe will need to cut the indexed butress 2mm per thread for the sleeve.

The lathe can also used to cut the undercut for the extractor hook. Just turn the chuck by hand for the proper rotaion, and move the form cutter into the bolt bit by bit as you rotate by hand.

A special drill for the tip of the firing pin hole.

A milling mahine with some form cutters for the bolt rib, and lugs.

A special mandrel to press into the firing pin cut to create the heical clearance to clear the flange on the firing pin.

Nothing that time, and money will not take care of.

James Wisner
Custom Metalsmith

Thanks Mr Wisner (and WRF)

I need a new bolt for a Mauser Kurz, a fellow has popped up here (down in NZ) who thinks he'd rather make a new bolt body than weld and shorten an old one. He runs a full machine shop and was an apprenticed Ferlach gunsmith so I was trying to ascetain if he was "blowing smoke" or for real.

Looks like it might be a good option if he will take some of the risk in terms of the time required to get it right.

Cheers - Foster

Shortening a bolt would be a lot easier then making one from scratch. If he had one in his hands he'd realize he's gonna need a few very special cutters to get the job done not to mention proper heat treating and finish machining.

quote:

Originally posted by Tentman:
Thanks Mr Wisner (and WRF)

I need a new bolt for a Mauser Kurz, a fellow has popped up here (down in NZ) who thinks he'd rather make a new bolt body than weld and shorten an old one. He runs a full machine shop and was an apprenticed Ferlach gunsmith so I was trying to ascetain if he was "blowing smoke" or for real.

Looks like it might be a good option if he will take some of the risk in terms of the time required to get it right.

Cheers - Foster

It would be far, far easier to shorten a bolt than to fabricate a new one. And no welding would be required.

I just don't see how this would be feasible unless he cuts a bunch of corners.

You "could" omit the guide rib, third lug, bolt handle(weld on later) and broached area in the front of the bolt that clears the flange on the firing pin. I believe all of these features have been omitted at one time or another on different Mauser copies.

I would much rather have a shortened bolt.

All of this talk about special stuff.

What did the Mauser boys do back in 1898?

quote:

Originally posted by 22WRF:
All of this talk about special stuff.

What did the Mauser boys do back in 1898?

The simple answer is that they did a bunch of special stuff.

I know that we are talking about the bolt body, and I don't recall the the exact number of steps, but the original 98 bolt sleeve required an unbelievable number of machining steps. It was something like 26 separate machining operations.

Interesting - how do you shorten a Mauser bolt without welding (or at least silver-soldering)

Cheers - Foster

quote:

Originally posted by JBrown:

quote:

Originally posted by 22WRF:
All of this talk about special stuff.

What did the Mauser boys do back in 1898?

The simple answer is that they did a bunch of special stuff.

I know that we are talking about the bolt body, and I don't recall the the exact number of steps, but the original 98 bolt sleeve required an unbelievable number of machining steps. It was something like 26 separate machining operations.

That would be about right for manual machines.

Lets just say this that back in 1898 when most all your machines tools are plain bearing, low RPM, using nothing but High Speed Steel as Carbide was too damn expensive. Doing things in fixtures and jigs was the key. To be honest the Bolt body was probably machined in a Horizontal mill with a indexing head that was geared to the machine to act as a fourth axis. This would allow the bolt to spin as the mill cut away material. It was quite a common practice for removing large amounts of material back in the day.

But what makes the bolt so difficult to make is it is not round. You have the lugs, a safety lug, a guide rib and a bolt handle all to deal with. with square edges meeting round surfaces.
It's not an easy part to make on conventional machinery let alone in 1898 and let alone today with the advent of fifth axis and CNC tools.

The other thing you need to think of is on those 26 separate machining operations most likely required a tool change and a fixture change or reposition not to mention relocating your tool center as they didn't have DRO's back then either.

There are many things built before the 1940's that I just shake my head at and wonder how the hell with conventional tools did they make that.
It required a lot of machine time and some very creative thinking. Something that is not easy to come by in today's machinists and tool makers. A computer spoils these guys and they don't want to learn trig. "Just draw it and measure it in the computer" It kill me every time I hear crap like that.
Remember the F16 fighter plane was designed with a Slide Rule. Try to find somebody that knows how to read one today......

quote:

Originally posted by Tentman:
Interesting - how do you shorten a Mauser bolt without welding (or at least silver-soldering)

Cheers - Foster

You don't/can't.

quote:

Originally posted by Tentman:
Interesting - how do you shorten a Mauser bolt without welding (or at least silver-soldering)

Cheers - Foster

Well, actually I was thinking of silver-soldering when I wrote that.

But I believe you could press fit the assembly. Not that there would be any reason to do so.

well he did say welding. but you would have to at least solder it. But just to get creative you could turn back a section of the bolt ad thread it left handed male on one side female on the other and screw the halves together.

I am by no mean recommending this to anyone and I'm not endorsing it as safe. the question was Posed and I answered.
IN theory it would work

quote:

Originally posted by kcstott:
well he did say welding. but you would have to at least solder it.

Not that I know what I'm talking about, and not that I would do it, but I think the bolt would hold together fine if it were press fit.

The way I have seen a bolt shortened is to bore the rear of the bolt and turn the front behind the extractor collar grove, leaving enough clearence for the solder to flow and fill the joint. I would think the bolt would be just as strong if there was a slight interference fit and no solder.

The only drawback that I can see to this method is that you would have to have everything lined up perfectly the first time. Unlike a soldered joint there would be no "do-overs".

Hmmm (again) or pin it like a Savage but I think we digress away from the original question.

Thanks

quote:

The other thing you need to think of is on those 26 separate machining operations most likely required a tool change and a fixture change or reposition not to mention relocating your tool center as they didn't have DRO's back then either.

Hmm! Not in Britain at least. If you look at (or speak to anyone still alive) who worked at "the BSA" in Birmigham they'll tell you this.

That there were people who spent YEARS on one machine that did JUST ONE cut or mill or hole. Then the item went in a tin box with however many others to the next man who added another single cut or mill or hole and then to another man who did the same and then to another and so on until eventually a finished bolt resulted.

If you look a pictures of BSA or of Manufrance (in France) you'll see literally a factory FULL of lathes or milling machines just each one doing one single operation.

The work was very boring and very repetetive.

RE. Shortening bolts.

I have rebuilt over a dozen pre 1964 M70's over the years, and yes one dammaged Kurz mauser bolt as well.

I would make a complete new bolt head from 4140 steel, it is designed so that the joint is at the edge of the extractor collar. The damaged bolt head is cut off, and the slip joint lathe turned. The two sections lined up and soft soldered or even loctited in the proper radial position.
Then and this is the hidden secret from the Reminton M700, one or two 1/8" holes are reamed in the side of the joint, and I use 0-1 unheat treated drill rod as the rivet to prevent any movement of the new bolt head.

I also have done about 40 replacement/rebuilt Remington M788 bolts this way.

I had to laugh about 4 years ago, a good local gunsmith brought a blown up 22-250 M788 in for a new bolt head, I pulled the bolt out and looked at it and told him I had already reheaded it once. I looked it up and yes 14 months before. Of course his customer blamed his brother-in-law for the damage, rather the HOT reloads he was using. Was able to rehead that bolt one last time and move the pins in a differnt place, have not seen it back yet.

One of these repaired bolt/guns can be seen in one of the older Leupold cataloges, it has the sides of the rear sight barrel lump cut down so it is smooth on the sides but still has the fold down rear sight, restocked in a nice custom stock, otherwise a factory barreled action. That was done for Gary Williams a former Leuopld sales manager in the 90's.

By making a new bolt head I could leave extra metal on the lugs and bolt face, and then fit the new head to the set back receiver to reheadspace the existing barrel. The worst M70 I saw blown up was a 220 Swift. The receiver vs lugs section was set back about .009", that I was able to recut the receiver lug seat, and then fit a new rebuilt bolt to it.

James Wisner
Custom Metalsmith

IMO it would depend upon exactly what equipment was available and how comfortable the smith feels with each process. Apparently your smith doesn't feel comfortable with the welding/silver-soldering process, so - no point in trying to make him do something he's not happy about.

Speaking personally, I'd cut-&-splice 10 times before I'd completely fabricate once. In my mind it's the difference between a one-off and multiples.
Regards, Joe

Buy a lottery ticket...

I saw two actions that a gunsmith in SLC had cut and welded to produce a true magnum length and a shorty. Guy was amazing. Built a bench rest rifle out of the short one, and a 450 Ackley (IIRC) on the long one. His name was Steve Fotou and he is in the Seattle area these days. I sent him a set of patent drawings for a Borchardt from the Logo & Trademarks Office, and a year later he shows me the Borchardt he built from those drawings.
You got to admire craftsmanship like that.

Rich
DRSS

quote:

Originally posted by Tentman:
Hmmm (again) or pin it like a Savage but I think we digress away from the original question.

Thanks

Sorry, I thought the original question had been fully answered.

I think some of us are just scratching our heads at the idea that someone would choose to fabricate a new bolt instead of cutting and splicing one.

Splicing the bolt would require simple 3 machining steps and then soldering. Fabricating a new bolt would require at least 10 times the machining operations(plus welding the bolt handle) and nearly every machining operation would be a more complicated than any of the 3 in the splicing operation.

BTW, how much did the gunsmith quote for the new bolt?

Probably as much as a new rifle.

A replacement bolt from a manufacturer is around $250 retail and a used 98 is around $100 striped.

If some one was serious and had cash I'd charge T&M and it would not be cheep even at $40 an hour.

I was thinking though any machinist worth his salt can make a part off of an existing part no print needed, And he damn well better be able to know what machines he would need to do it right.

Thanks for your thoughts guys.

Sometime I can make things more complicated than they need to be and this may be one of them . . . BUT

Its a genuine Oberndorf Mauser Model B sporter (Kurz) in 250 Savage, its in beautiful original condition apart from the missing bolt. These are very uncommon generally, and dammed rare in the condition mine is in. If it had its original bolt I'd think it was worth around NZ$3000, and almost certainly US$3000 + in the US. Maybe I'm dreaming but I don't think so.

So I think it deserves the best, if I was stateside I think I would send it to a "name" smith for a shortened bolt, which I am reliably informed would set me back minimum US$600 to $1000.

The quote I have for a new bolt body here in NZ is NZ$1250 (thats US$800). If he does a good job (and the purpose of this thread was to try to get a feel for the risks) then I think I'll be ahead. If not then so be it (and I'm still weighting options). The guy is operating a full machine shop as a precision engineer and was a trained gunsmith via a formal apprenticeship. He's relatively young and I don't know the quality of modern euro appenticeships but the old ones were mostly wonderful craftsmen.

I see a new bolt (if of high quality) as setting the rifle back to "original" and a worthy contribution to its provenance. A shortened bolt is sort of like a playboy centrefold compared with a Ruebens original - to paraphrase P. C. Bolger.

Cheers - Foster

quote:

Originally posted by Tentman:

I see a new bolt (if of high quality) as setting the rifle back to "original" and a worthy contribution to its provenance. A shortened bolt is sort of like a playboy centrefold compared with a Ruebens original - to paraphrase P. C. Bolger.

Cheers - Foster

I have no doubt that your rifle deserves the best. Kurz Mausers are almost mythical.

I feel that on original Oberndorf bolt(made form the original steel, original machining, original heat-treating) that is shortened to fit your receiver is as close to original as you are likely to get.

A new bolt(even of high quality) is going to be pretty far from original. It will most likely be made of different materials which will require different heat-treating than the original, resulting in a different surface finish.