doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Fitting 2nd set of barrels without 3rd fastener

I have a 12 gauge boxlock with double underbites and a third fastener (straight slot engagement, not Greener).

I found a set of 16 gauge barrels with double underbite and the same center to center distance as the 12.(same firing pin distance). However, this barrel set does not have the third fastener.

I would like to fit the 16 gauge barrels to the 12 gauge receiver. Assuming that the barrels are in proof and fitted properly, would the lack of a third fastener prevent using the 16 gauge barrels on the 12 gauge receiver?

My guess is that the double underbite alone was strong enough for the 16 in the first place, so would be sufficient on the 12.

Would any mechanism on the 12 be damaged by not engaging in the third fastener?

Has anyone milled the rib and added a third fastener to a set of barrels?

Thanks,

I see no reason that your idea will not work. Fitting the barrels could be a real task, though. What kind of gun are we talking here? I do find it curious that a set of 16 gauge barrels would have the same center to center distance. Is this a gun that was commonly made in 12 and 16 on the same frame?

oganza, you may want to get in touch with Ken Duglan At Atkins,Grant&Lang. He has overseen a few fitting of barrels w/o the third bite. His MO has been to fil in the space on the breech face. Give him a call. By the way,who is that a picture of under your name?

Justin...if he fills in that vertical Purdey 3rd bite slot (If that's what it is), ....then his 12 bore's won't close.
I guess he could file off the below rib extension , then they'd fit?
Just kidding
franc

Here is a link to the gun that was previously discussed on the board.
http://www.doublegunshop.com/forums/ubbt...20649#Post20649

It looks like a nice english boxlock, with ejectors. No maker's name is present. Believed to be manufactured in Japan in the 20's or 30's.

The 16 gauge barrels are Spanish. I got them to practice rust blueing. I measured the centers at 25mm. The 12 gauge is at a 1 inch center (25.4mm), so the firing pins will be off .2mm or 0.0157in. I'm sure that would be close enough for the primers.

The underbite on the 16 gauge has enough material to be made into the same profile of the 12 gauge barrel. I cast the profile of the 12 gauge underbites into a polymer. I plan to use this as a rough guide to shape the 16 and then fit the final bit with hand fitting and lamp black.

Here are some photos of the 12 gauge.

http://i127.photobucket.com/albums/p159/baldferd/pix1686534173.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1686533767.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1933264001.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1686534251.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1686533970.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1933264267.jpg
http://i127.photobucket.com/albums/p159/baldferd/pix1933264204.jpg