Info needed, tightening a S x S shotgun action.
Hi all, I am considering the purchase of a mid value English, box lock, double barrel 12 gauge shotgun. The seller, (he is competent) stated that the action was a bit loose and needs to be tightened. To date I have not seen the gun.
Need to educate myself with this type of repair, so where can I find general information, books or articles.
Yes, at the moment I do not know where the wear point is, so makes it a difficult question to answer.
Your reply would be appreciated. Targetguy39@hotmail.com or (636)-797-4203
the most common area for a box lock to get loose is the lower lug and lug pin in the receiver. But I have also seen a few neglected box locks that had upper lock lug damage. Its a gotta see it situation. Can it be fixed? about 90% of them can. The others that can't is usually bc of a cracked receiver, broken lug or someone not knowing what they are doing got in there.
tightening a S x S shotgun action
If the hinge is loose, Shooting Times, had a piece on how to fix. It was a year or two back. It involved using a tapered pin and reamer.
I have seen this type of repair done by soldering a shim to the inside of the hook on the chopper lump.
theres a book by Ellis Brown , called making double rifle from shotgun frames, he shows how to fix that problem , has a lot of info on double's
Try going to the American Custom Gunmakers Guild Website, I beleive they have seminars on video/dvd on this.
Loose connection between the barrel and frame.
Usual situation is the hinge joint is worn and not setting the barrels back properly.
The options are to replace the hinge pin with a larger pin to compenste for ware or the build up the hinge part of the lug under the barrel. Depending on how the hinge pin was made and mounted will affect the decision of how to attack the problem. I have done it both ways on el cheepos just to learn how.
Pin replacement is no small undertaking. Many are cross pinned in blind holes and will have to be drilled out. Removal of the hinge pin may require a milling machine depending on the design of the pin because the surfaces are too curved to start a drill in. Replacing the pin is likely to require refinishing of the reciever because the new pin will have to be filed to match the profile of the existing reciever on most guns (not Parkers). This is likely to remove any finish in that area. Engraving of pins is also common on English guns, so matching that will be a bear. I would avoid this technique on case hardened recivers if the colors are in good shape.
Building up the lug with a shim and solder is an easier, and unlikely to affect any surfaces that show at the range, but hiding the thin silver line that results is another chalenge, It is likely to be detected on dissasembly. Tig welding is also an option for building up the lug. Some polishing and fitting will be required with either fix. Refinishing of the barrel lug (at a minimum) will be needed for either barrel modification.
Neither is a simple home owner task, both require some care and understanding of double guns.
Tricks to hide this problem inculde peaning or center punching the hinge joint on the bottom of the barrels to raise a burr that sets the barrels back. This is similar to a cheep valve job on an engine.
On some guns you can also clamp a piece of slightly oversized round bar against the water table and pean the edges of the watertable over where they contact the lump on the bottom of the barrels. This prevents side to side movement.
Neither are real fixes and ware out in a few shooting sessions, leaving the gun in worse shape than where you started. The tricks are employed by some to get a gun off the table at a gun show, so watch for burrs or modifications in these areas. Is unlikely you will encounter this on a higher end piece, but stuff thats cut down for the cowboy action game is another story.
The hinge area on the lug is machined away, and a bushing with 2 correct radii is silver soldered in place, on location.
This is regarded as an acceptable fix among British gunsmiths. It involves more time in inspection and knowing where to mill than actual steel cutting.
I hope this makes sense.
I would second the opinion of Mark. As he said, the measuring of the relationship, between the breech face, and water table, and the hinge pin, will take some time, and tools such as a height gage, and test indicator, an angle plate, some type of clamp, and strips of aluminum, or brass to protect the receiver surface from the clamp.
I, also have a copy of the book about building double rifles, from shotguns. I think that the author has done a very good job of explaining, and also illustrating, the steps, as he goes forward.