doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Putting a set of Fox barrels back on the face

Putting a set of A H Fox barrels back on the action face

Barry Lee Hands had such a well-received series of photos a few weeks ago; I thought this might be interesting:

The fit of the barrels to the action and it’s face is comprised of the fit of the hook (hinge) of the barrel lump to the hinge pin and the fit of the locking bolt to the lumps holding the barrels tight to the face of the action. Some guns need a new bolt fitted to lock the barrels to the face of the action, other need to have the hook/hinge pin fit addressed , and some need both. What is needed is a subject itself and I won’t cover that here, but I will show you the procedure I use when it is determined that the hinge pin/hook fit needs correcting. This is the method I use to do this.

The procedure entails first taking measurements of the barrel lump and hook and the action; building up the hook on the lump with weld, rough boring the hook diameter to fit the pin; file fitting the hook to the actual pin, and blacking down the face of the barrels to the action face. This is a simplified series of the steps involved, not a tutorial, that results in a proper fit of barrels to the action face, is permanent and no trace of repair is evident.

The first photo shows an AE fox 16 gauge with quite a bit of looseness; I have inserted a .004 feeler gauge between the barrels and the face of the action. This is the greatest gap and shows the barrels will have to be set back at least this amount, plus a little for fitting to the face. This gun rattled a lot.

http://s303.photobucket.com/albums/nn132...89_0047_047.jpg

Photo 2 shows the lumps of the Fox barrels with my “gauge piece” picking up the rear of the lump; a pin is in the existing hook (or radius cut for the hinge pin). I can measure the distance from the pin to the gauge piece, which gives me a measurement for re-cutting the pin hook.

http://s303.photobucket.com/albums/nn132...85_0027_027.jpg

I have not shown a photo of the welded hook cut in the lump, forgot to actually, but I think you get the idea. The entire hook is built up with a mild steel filler rod. I use a Miller TIG torch with argon shielding gas. I can weld up the hook in one pass, the heat is so concentrated I can do this without flowing the tin solder on the ribs, and , of course not effecting the braze joint of the lump to the barrels. Or barrel blacking. I do go back in and weld a bead on each side of the hook cut to make sure I get a good weld with no voids that would show. After welding I mill the sides of the weld close to the sides of the lump and finish up with a file and abrasive.

Now I can ink up the lump, take my gauge piece, reinstall it like in photo 1, and scribe a line using my original measurement plus the set-back required plus what I need for file fitting. I am going to cut the hook a bit forward. I other words, I cannot go in a bore out a hook and have it fit properly. Is the hook cut square to the lump? Is the pin tapered?

Photo 3 shows the barrels set up in the mill and a boring head, set to hinge pin diameter, boring out the hook to my scribed line. Hope this is visible. After boring the hook I have to start file fitting the hook to the pin in the action with smoke to show contact.

http://s303.photobucket.com/albums/nn132...83_0017_017.jpg

Photo 4 shows the barrels pointing up in the vise and the hook smoked; you can see where contact has removed smoke. This smoking and fitting is the essence of the fit: smoke, try, file, smoke, etc. But you cannot just fit until the barrels close up as you have to fit the barrel face to the action with smoke to get that right also. Actions seen to open up on top due to firing stresses.

http://s303.photobucket.com/albums/nn132...87_0034_034.jpg

Photo 5 shows the finished hook after fitting.

http://s303.photobucket.com/albums/nn132...02_0025_025.jpg

Guns with removable pins don’t need all these steps, but on guns with non removable pins, I think it is a lot less work to weld up and refit rather than make an oversize pin as there is no engraving to be dealt with, or enlarging the pin hole in the action. You still have to fit the barrels to the action face.

There are other methods used to accomplish a proper fit, this is just one.

Hope this proves interesting.

Thanks Mr Potter...It is always enjoyable to see how a quality gun smith fixes these problems with older doubles "correctly"...

Many thanks Dennis. I'm going to do this on a Parker for my first time. Your tutorial, along with Steve Bertrum's is very helpful.

Thank you, too for posting this. Very informative.

Dennis is who I learned from....Thanks again, it sure has me helped me out over the years.
Steve

Thanks for taking the time to post this! It is very informative for a rifle hack like myself. I for one am eager to see any of these short tutorials you have in mind. I would like to do a little double gun work soem day and seeing this is very helpful for me.

Mr. Potter,

How do you decide if the gun needs only a hook/pin refit or it also needs the underbites refitted?
Thank you for your help.

Silvers, You can tell what is worn by applying a temporary shim of paper to the hook.

This is one of the many valuable skills you can learn at Dennis's class in Trinidad CO.

http://www.nragunsmithing.com/trinidad.html

Thanks, Dennis, for taking the time. That was most interesting. Do you fit the barrels to the action face with the extractors in place, or do you fit with them out?

Mark,

Thank you for your tips. I wish I had time to go to courses like that.