doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Loose action Boswell

I have a late 1940's box lock Boswell 12g double gun that has become very slightly loose in the action. Holding the gun by the stock with or without the forend in position and shaking it from side to side creates a little movement between the chamber face and breech face. I've held the gun up to a fluorescent light and cannot see any light coming through the join between the breech face and barrels.

My gun has a fixed hinge pin that can't be replaced. Another alternative that I've read about is laser welding of the hook that fits around the hinge pin to build this area up. I've also been told by a reputable source that if laser welding is done, within about 3 months of use the gun will work loose again at this point and isn't recommended.

Any thoughts or suggestions would be appreciated.

Reidy, I cannot imagine a gun working loose after three months of casual shooting after having been laser welded and rejointed, though I have never had it done. I have a Hollis that I plan to have welded, and will rejoint myself. I will have the hook micro-tig welded, as opposed to laser welded, but welding is welding. Both processes are applying a very thin layer of steel to the worn area, then removing until there is a like new fit.

I'll be interested to hear other's experiences, and comments. Especially those of actual gunsmiths, like Steve. Great question.

Laser welding was coming into common use around the time I retired so have had very little experience of it .
The success of any welding will depend on the welder and the material use as a filler ,for this a low carbon such as En8 .
With solid pin guns its always worth checking the hinge/joint pin has not worn oval and may need to be dresses back to concentricity first .

This might help.

Here we go!

If a new joint pin cannot be made….

I use laser welding. I can specify exactly how much material that needs to be added into a specific area, it seriously cuts down on the time it takes to get the barrels back down onto the action. I have not had any issues with the laser welding material not holding up. I have a Lancaster that was put back on the face 13 years ago by laser welding. It’s had thousands of rounds through it since then (it was used for a decade as my main hunting & clays gun). It’s still smack on the face.
I recently rejointed a Churchill by using the same method and am sure it’ll wear exactly like the Lancaster. The difference between laser welding and Tig welding is the amount of heat subjected to the lump. Laser welding is a much cooler, much more precise process IMO. My laser welding guy goes about this in a scientific way to include his knowledge of specific metallurgy.
I would not take a set of barrels to a jewelry store (jewelry stores often have a laser welder) and ask them to laser weld a hook. I don’t think they are quite as precise as a laser welder who welds for the aerospace & nuclear industries.

One of the things I’ve noticed about the old technique of spray welding is that the material used is so damn hard, you HAVE to use diamond coated files to work the barrels down. I think that’s why some fixed joint pins would start to concave, because the spray weld material is so damn hard. I have no proof of that, just a theory.

AHHHHHHHHHH!
Never been able to watch one of these videos all the way through without screaming .

I used spray welding to good effect in the past . All depends on the spray medium as some can be very hard so I had to be careful to make sure I had the right bottle on .

In defense of old Jack, when he was trained there was no TIG or laser welding so he had to be a bit of a blacksmith. His techniques seem crude and certainly aren't best practice now but they do work. I've used them. Some people have little money and some guns aren't worth spending much money to fix. I'm glad Larry Potterfield documented the old way. Didn't we go through all this about six weeks ago?

Yea, we did.

At that time, I referenced the DGJ article on the Nitro Special guns, and the author who got the very well worn 12 gauge in about 1964, that was loose, who then fixed it with a little piece of .004 brass shim stock betwixt the lump and the pin, who then used it for 30 seasons or so as his duck gun, with hot 2 3/4” loads. The gun was then sold to a guy who was told about the repair, and who proceeded to do the exact same thing with it for a few more decades. It might still be in use with that $1.00 repair. It wasn’t loose when he sold it.

I guess, if I had a low end gun that was loose, I’d do the shim thing before beating the lump with a punch. In the meantime, I do put a little smear of Mobilegrease 28 on the hook of every double I own, hoping to keep the wiggle away.

Except the Darnes. They don’t get loose.

Best,
Ted