Gunsmith welder - looking for one

Wouldn't tig be better for such a task? That's what I would try myself..... But I am no smith, just a hobbyist, and part time welder lol
 
hi
just some thoughts
what was the parent metal on the bolt ? steel / iron / alloy ? this would matter in matching up the electrode material to the parent metal
- also, welding leaves the grain size in metal very large... it would have to be normalized/heat treatment to reduce grain size
( large grain metal = lack of toughness )

-is the bolt heat treated for hardness ? and what rc

if its just reg mild iron ... then i imagine mig is good
- if its steel, you can use a similar metal to the parent metal as feed stock when tig welding ... so that would be better
- then the whole bolt can be re-heat treated to similar spec as all the material will act the same

it can be done... but these questions should be thought about



just some concerns
 
Was looking to get a bolt repaired in this manner. The best alt I could find was a what the tool and die guy called micro welding. He said it was done with a TIG and the fill was added in VERY small amounts. He said he didn't think it would mess up the temper too much but wouldn't say for sure as it's not his area of expertise. I'm still thinking of persuing this. I've since found a bolt but if it works you can't have too many spares...
 
^ Issues: "material type" - fair enough, you would think someone out there with Laidlers book would chime in on that.

Failing that, we are back at educated guesses - I would say the steel making up the BOLT HEADS is something like 4140 steel.

There is NO NEED to re heat treat THE ENTIRE BOLT. see we are already straying far afield. Lets not confuse someone who might actually try to re-heat treat the entire SMLE BOLT BODY at home.

My bolt head has a distance of 0.629 from front to back WHERE IT MATTERS.

Just 5 mins ago, I slipped a shim made from the typical white on one side aluminum flashing material between the bolt head and the cartridge head and it just barely closed.

The thickness of the shim material as measured on a Mitutoyo dial vernier showed a reading of 0.019-0.020".

This means I would require an un-messed with bolt head of at least 0.650 to get the head space acceptable again.

Steve of 303british dot com recommends cutting exactly one revolution of the threads off the barrel & setting back the knox form shoulder by the same amount. The receiver ring would also have to be trued up. Then you would have to use indexing washers to take up any slack, then you would have to re-cut the extractor groove and re-cut the chamber.

Assuming you got a competent gunsmith who did not spring the action or bend the barrel while removing it, you are up to probably 400 bucks of labour already.

Then you have a franken smle.

This is not a sporter SMLE I am trying this on, it has a full woodset.

This is not a Drill Purpose rifle I am working on, it was FTR in 1953.

*Damned Elbonians must have all the un-messed with SMLE bolt heads. :mad:

Edit: I am not angry, I don't want improper info posted that might get someone in real trouble. Thanks. :)
 
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i imagine if you could find a scrap bolt from a similar rifle ... this could be cut into stripes with a bandsaw and used as filler stock for a tig weld
- then there would be no guessing at the alloy !
 
Barring some of the more traditional options you have already mentioned above, some have found success through thermal spraying the bolt face.
 
Yer not gonna weld, braze or solder on a bolt head without frying the thing. At least, it WILL get hot enough to draw the temper of any hardening it had prior to welding.

Do you know what the Rockwell hardness should be when all is done?Case hardened, or through hardened?

If you get it hotter than you would touch, willingly, you are getting in to temperatures that will draw temper, say, anywhere upwards of 350 deg F.

On a small part like that bolt head, even with the best heat sink material packed around it, it's gonna get hotter than that if you expect the weld to happen.

My bet. The bolt heads were made of a low carbon steel and were case hardened at the factory. Failing that, they would have been some form of medium or high carbon steel, heat treated according to the theories of the day.
Remember that the metallurgy of their day was not too complicated. Simple, cheap, and available, were the operative principles.

If you were in an area that had a tool and die industry, I would suggest looking for a die welder that could TIG the build-up on the bolt face. It would provide the cleanest most accurate application of material, and the filler rod could be chosen for the material needed.

Hows the bolt locking lugs?

It's a doable project, but getting someone to do it for you is going to be a bit of a search, as you know. Some won't touch it because it's gun parts, others due to liability concerns, etc.

Maybe it's time to start building your own, with a small lathe and mill.

Cheers
Trev
 
For What It's Worth - the Lee Enfields have a rear locking bolt - the lugs are at the back (nearest the bolt handle). The bolt heads on Lee Enfields are screwed into the front of the bolt body. There is a series of heads that are/were available that were increasing lengths. The idea in the field was that the unit armourer could check headspace, then for worn units (excessive headspace due to wear), he could screw out the head on the bolt and replace it with a longer one, bringing the headspace back into spec. So, fat tony was talking about building up a bolt head - a piece that is completely separate from the bolt body. The longer heads are getting quite difficult to find.
 
fat tony said:
I am looking for a competent welder who can mig weld the face of my SMLE #1 MKIII* bolthead please. Not looking for guarantees from the nanny state at this time. :D :pirate:

Before posting snyde comments, pls. go to this thread and read post # 47 :)

http://castboolits.gunloads.com/showthread.php?134927-shim-SMLE-bolthead/page3

Wondering if Epps does this. . .
Click to expand...

Hi Tony...

I am no SMLE expert.. I only have an FTR No4 MK1/2, but I have had similar issues on other types of parts..

That being said, just as a wild suggestion, have you thought of some kind of plating? As an example, here is an excerpt from a web FAQ:

What's the Maximum Thickness of Hard Chrome Plating?

Q. What could the the maximum thickness of hard chrome plating that can be deposited on ferrous metal after which the layer starts disintegrating?

Is there any measure of adhesion which can be checked, if so, the method to check?

A. If properly applied, there is no set limit to the thickness of hard chrome, but as a general rule, chromium is most stable on ferrous alloys in the range of 0.0005 to about 0.025 in a single application. Chromium deposits over 0.025 per side can begin to become rough with build up at edges and pitting. Success with thick chromium deposits has a lot to do with the initial surface finish of the base metal.

When applicable, "after plate finish requirements", i.e., uniformity, mimimum thickness, surface micro finish and micro-crack acceptance level, dictate the best chromium procedure to follow. The initial set up, tooling and especially anoding procedures, are critical steps to achieving the most success.

Chromium deposits can be applied in numerous ways, with a variety of results to achieve specific customer requirements. One such procedure is to apply a layer of chromium over top a layer of nickel, when coating thickness requirements exceed 0.025 (per side).

Just a thought that perhaps you could plate just the face? or perhaps everything, or just forward of the threads... Just a thought anyway, kinda outside the box but it did really work wewll to tighten up a frame/slide on a pistol for me.

good luck
 
Nothing at all. It would involve rechambering and deepening the extractor cutout, and you would have perfect headspace if the job were done properly. Better than fooling around with welding and re-machining bolt faces. Probably not a lot more expensive either.

Having said that, I can remember Elwood Epps advertising chrome plating bolt faces to correct headspace. That was more than forty years ago! :D

Ted
 
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OK, I hesitate to drag this up, but I have an idea and I would like some honest feedback. Full disclosure time. I am an amateur, and I am not a welder. But I have a 1915 SMLE with headspace issues, and I have been mulling over ideas for fixing it. Here is my latest one.

I have a bolthead that when tight sits at almost 11:00 (looking down the bolt from the back) so I figure it is pretty much pooched anyway, and I am willing to sacrifice it for the experiment.

So my plan is to back it out a turn until it lines up properly, and then with feeler gauges figure out exactly how big that gap is, and get a steel washer style shim made to that thickness. Then, assuming there is still enough metal to work with, hone the bolt face until it will close on the .065" gauge.

The advantage I see is that there is no monkeying with any heat treating.

Is there any reason why this plan would not work? And please be gentle with a noob ...
 
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