doublegunshop.com - home Forums Thread Like Summary - MAC SXS Shotgun - manufacture nat. d'armes de chat

I picked up an action recently pretty cheap. Well an action and a stock. No barrels and no forend. I've been playing with the idea of making up a block, and using a couple barrel blanks. I machine injection molds for a living, so I am very familiar with how much work it would be to reverse engineer for this. Lets lean into the idea of doing it rather than discouraging it because its hard. I know its hard. LOL.

I've already waded through a few threads on French shotguns while I was waiting for membership approval. I'm not seeing anything like a parts diagram. What I would really like if somebody would be so kind is to post some decent photographs of the barrel hardware and the forend hardware.

Yes, I checked the usual sources. Numreich, Jack, Sarco, Ebay, Gunbroker and more. Didn't really find much. A couple "shotgun unknown" items might be similar. For this discussion lets please, "lean into the idea of doing it." I may decided not to, but my goal is hopefully to gain more information on parts and only then consider if I want really to machine, solder, and hand fit or not.

Could you post pictures of the action and flats with measurements? The length of the watertable, distance between the firing pins and the way it cocks and how it locks up. Also the diameter of the hinge pin and what the radius of the knuckle are all things you will need to know, and us to help.

There is a book that a guy welds a new lump on a barrel set to fit an action I don't remember what book.if you can machine a lump and you weld it might be a less labour intensive fix.

Bob;

Are you asking for help for making a "block" that will have the lumps machined into it and also where you can add barrel blanks to this block? If that is what you are asking and if you have a vertical milling machine you can build what is known as a shoelump style "block" to do what you desire. Look down through this old post (see link below) of work I did some years back in building a shoe lump barrel set. You could machine such a shoelump block in plastic as a prototype.

Kindest regards;
Stephen Howell

http://forums.nitroexpress.com/show...al&topic=&Search=true#Post297834

It is always nice to see a good build thread.

The weight savings from a hollow rib not only affects the overall weight, but also the balance.
Mike

Welcome to the forum, Bob. Thanks for sharing the info with us, and I wish you the best in your endeavor. I can appreciate your desire to do this. There are some sharp people on here (I do not include myself in that group) concerning gun building. Be patient. Maybe some of the more knowledgeable here will see your post and offer something that will help.

Best wishes on gathering the info to tackle this venture.

https://www.armslist.com/posts/1004...ac-acier-special-16ga-sxs-france-shotgun


https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=37702&page=all

Bob,
First of all, Stephen Howell did(does) fantastic work and I am not denigrating it at all, but I believe you will find it much easier to make a Monoblock instead of shoe lump type block. The obvious difference between the two types is that with a Monoblock, the barrels are inserted into the Monoblock and the "joint is large enough that soft solder is sufficient to hold them, avoiding the possibility of overheating the barrels. The often-voiced objection is that there is sometimes a visible joint, but not everyone finds this objectionable. If you can remove the hinge pin, and locking blocks, the receiver will tell you the dimensions you need to mill the Monoblock. I believe barrel blanks already prepared for use with a Monoblock are available as a special order from Walther. The diameter of the holes in the Monoblock should be determined from the end of the barrel blank.
Mike

I suspect you will find more interest once you start work and post photos.
Mike

Post your progress and see what happens,

I have had to use old shotgun barrels to sleeve sxs,I try and find a set of cast off double barrels that are at least mid 20th century steel they are soft soldered and brazed at the breech also you end up with ribs,Belgian barrels sometime have the ribs brazed I think some Stevens have brazed ribs.good luck on you project .im up in showlow

Bob,
If you take mc's example, I suggest you go to the Walther website, I think you can find the German standard and tested dimensions for turning the chamber end of the barrels. At the same time you can " pick out" the diameter of the reamer you will need for the final sizing of the holes in the monoblock.
Mike

Heat up the rib and see if it falls off . I have been looking for barrels like that only 30 inch or more

You can use conduit for the bottom rib. Cut and fit anf remove the outer coating and solder it on.

Der Ami & MC;

When I need rib material for side x side guns and rifles I decide upon the contour of the of the rib that I want and the wall thickness and then calculate the diameter of a steel tube that has that or near that contour, (say 2 inches diameter) and then I buy (usually from eBay--although it will sometimes take a day or two to find someone selling it) seamless thin wall high strength tube lengths (say .049" wall thickness) that are scrap from the shops of automobile race car builders. I think all of the times that I have purchased these tubes it has been from some of the North Carolina race car building shops. Really nice and very thin wall "stuff".

Kindest Regards;
Stephen Howell

Emt

Emt is cheep thin easy to cut for the bottom rib ,the top is more difficult to make it should be hollow to save weight .english guns had the ribbe's tinned on using pure tin ,tin with lead flows a lot easier I was told the reason pure tin was used is that it expand and contracted similar to steel,used in barrels .

Yes. The size that I like is 1 -7/8 inch O.D. chrome moly alloy steel with .035 inch wall thickness.

Kindest Regards;
Stephen Howell

In theory if you bore the monobloc for the barrels so the barrels touch at the muzzles and the center of the bores are level you will be really close.