Gunsmithing TIG'n Bolt Handles

[woodsy]

Trued a 700 receiver today and the gap between the bolt handle and receiver went from 0.010 to 0.021. Yes, the receiver's lugs were off just a bit. This one must have been machined on a Friday afternoon . . . late.

Obviously this handle needs set forward. I've removed it and cleaned up all of the silver solder so it can be reattached by welding. There's a Miller Diversion sitting in the shop but I'm not used to doing such detailed work. The MIG and stick sees the most use around here but I'm thinking about tackling this thing with the TIG anyway.

The smallest electrode that I have around here is 1/16" and I should be okay on filler rod. There should be a 3/32" electrode in there as well. Not sure that size it is but I have a pretty small cup that should handle the job.

What are the experts using? Are you welding the entire perimeter of the handle or just underneath the stem and the opposite end? Do you undercut the part first?

Sorry for the silly questions but this is a bit foreign for me. I can run a MIG and stick like a banshee but I’m still a TIG newbe.

 

[300sniper]

really want to know what i'd do?



























i'd be calling ptg on monday and getting a true one-piece bolt on order before i fit the new barrel. eff two piece bolt/handles. soldered, tig'd, screwed. they all have the potential to let you down at the worst possible time.

 

[woodsy]

Oh, trust me, I've thought pretty hard about doing just that. I may just fire up this welder and see how things turn out. Nothing ventured, nothing gained . . . right? PTG will always take calls.

 

[MikeeBooshay]

Well if you are going to try anyway - and it seems as if you know a bit about TIG already, here is what Mikee would do:

1. Clean and degrease completely - a bit of grit blast, or clean stainless wire wheel on a Dotco grinder.
2. Slight weld prep - an .030 chamfer on the handle, nothing on the bolt.
3. Make a test run without the trigger installed - ie, tack it up, insert the bolt, check gap, and primary extraction.
4. Using smallest tungsten I have, weld it up, with enough heat to get good penetration, enough filler rod to get a good fillet. Somewhere I have seen an aluminum heat sink for this very job, to help keep the rest of the bolt cool, probably take a few minutes between passes. Most of your arc will be on the bolt, not the handle.
5. I would weld all four sides, so if I had to blend any, there would still be plenty of strong left.

Then I would think " next time, before I go to all this, I can call Kiff, and get a one piece bolt that fits in the bore as well as timed correctly!"

I would probably try it anyway though, you will learn something and get better in the process.

 

[E. Bryant]

What are people using for fixturing when performing this work?

 

[WhiteDingo]

I use the receiver itself to time and get alignment, then a small set of needle nose locking jaw pliers (ground contoured to match the bolt inside and smooth to not marr the handle) to clamp in place, then tack it and double check.

 

[woodsy]

Well . . . I got her welded but will be calling Kiff tomorrow anyway. I discovered that I really need a tad lighter shade in my helmet (or brighter lights) and need to be wearing cheater glasses when doing such detailed work. It was a bit difficult seeing the tiny puddle. The welds turned out fine but I'd have to do quite a bit of dressing to get it to work/look like it should. Put down just a bit too much filler but one thing's for sure, it's on there to stay!

Yes, I did get to Mikee’s “next time, before I go to all this, I can call Kiff, and get a one piece bolt that fits in the bore as well as timed correctly” but it was worth the trouble. You can’t learn anything by keeping a welder unplugged. Making heat is the only way to improve.

The only thing that sucks is I’m behind on this .260 build yet again. I doubt Dave has what I need in stock. Crap! I really wanted to be shooting this thing next week. Oh well.

 

[E. Bryant]

woodsy,

As of this moment, Midway has PTG bolts in stock with the .473" bolt face:

PTG One-Piece Fluted Bolt Handle Remington 700 Short Action 308

FWIW, I have a couple rifles sitting around with PTG on-piece bolts, and they are undoubtedly the way to go. That being said, I also have a nice TIG welder, and will someday decide to use it in the pursuit of fusing a bolt body to a bolt handle. Sometimes, the right way just ain't interesting enough

 

[Turd in the Pool]

I discovered that I really need a tad lighter shade in my helmet (or brighter lights) and need to be wearing cheater glasses when doing such detailed work. It was a bit difficult seeing the tiny puddle.

Stereo microscope is the way to go. Hard to justify the cost if you don't do a bunch of gun welding. A good one runs about 2K.

I bought a chiwan model 10 or 15 yrs ago for $350. Had to make the UV lens holder but it works well.

It allows you to see so well that you don't need filler rod. Fusion welds will hold them on.

Don't know if any have passed the hammer test but so far, none have come off.

Also, a turning mandrel screwed into the body helps a bunch for heat.

 

[woodsy]

Hum. Not sure about the mini 16 extractor. To be honest, I've never had any problems with the stock setup. Is this a significant upgrade for extraction or a solution looking for a problem?

 

[Gene Poole]

Hum. Not sure about the mini 16 extractor. To be honest, I've never had any problems with the stock setup. Is this a significant upgrade for extraction or a solution looking for a problem?

Some swear by it, but it seems to me that it negates a key feature of the R700 design in that a catastrophic failure of the round will not be contained by the bolt/bolt-recess, but shoot that m-16 extractor right back into your face.

 

[CowboyBart]

I've had/have guns with both the Sako and M-16 style extractors. I like the M-16 style better. It is a solution for a non-problem but on both of mine I had to open up the bolt face to magnum. In doing that the OEM style extractor goes away. I guess the guy who opened up my boltfaces could have put a groove to hold a factory extractor but I went the "claw" route.