doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com 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.

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.

Mark II, I will certainly get to that at some point, but right now I am in data seeking mode. At this point I think its unlikely I am going to luck into the right parts, so seeing images of the mating parts I don't have is more useful.

mc, I can reverse engineer and machine. I can shoot metal out of a hot glue gun for metal. Sometimes it looks good, and sometimes it looks like what comes out of the north end of a south bound chicken. I have considered the approach of cutting off and welding on hardware to some other barrel set, but if I build from scratch I think most barrels are silver soldered together. Also within my skillset, although I am no master at it.

Stanton Hillis, Thank you. I am sure there are.

skeettx, I missed your armslist link when I first read your post last night. That looks like exactly the same shotgun. The forum link you posted is actually the first thing I saw when I first visited this forum from a search engine result for the first time. I have not read every word of every post in it, but I will. I have skimmed every post, read many of them, and looked at some of the images.

Thank you all for your help.

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

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

bushveld, I looked at the first page of your thread on the other forum and noted the use of a D-bit in your pictures. That made me smile a little. I've been learning to make my own single lip cutters for special applications to reduce the number of setups for some jobs. Special dovetails for tool holders, angled faces that can be programmed flat in a cnc mill instead of tilted in a sine vise, etc, Stuff like that. I make such tools out of broken carbide, because, well I have a lot of broken carbide. LOL. I do have a vertical mill or two or three or ... well 5 currently in regular service. Another one for only those emergency repairs on a day when I have a broken air compressor, and one more that had a catastrophic ball screw failure I haven't gotten around to fixing yet. Even a small one still in the crate I bought just to do a video series I haven't started yet. I think that makes nine including the retired one on a shelf. They range from toy to light industrial in size (2 tons). No really big machines. I might have a lathe or two as well. I make a living using them. Someday I might get good at it. I just read a few of your posts in that thread and I can see where there will be a great deal of good information in it. Thank you.

Der Ami, Thank you. When you say soft solder I have to assume you atleast mean plumbers solder. I can't imagine using 60/40 unless it was just to gently hold pieces that are mechanically wedged in place... and yes I can see how the barrels might be mechanically wedged into a mono block. Or atleast what I picture in my head as a mono block.

I'm certainly not certain of exactly how I will tackle it just yet. I might even have a fantasy of just lucking into the parts... like fantasizing about winning the lottery.

Bob,
As I recall, it was 50/50 solder. The Monoblock/barrel solder joint was large enough that it was plenty strong enough to hold them together. My experience with this was in the mid 1970s to early 1980s. I highly suspect that now they would use a high strength glue such as Loc-Tite bearing fixer (I think it is their #662 or 668). I recently lost a friend that converted double shotguns to double rifles, using this glue. Due to a mistake, he had the need to break the bond of this glue and he had to heat the barrels/block to bright red to do it. With regard to machinery, you would be surprised how little was required. My German gunsmith friends used only a small "speed lathe" that had a shop-made bed extension when replacing barrels using the old ones to make the "block" ( hakenstuck?). This lathe had no carriage or lead screw. This was before reunification and if they made a new barrel set for an East German gun that no blank sets were available for (Merkel, etc.) The used a small horizonal spindle mill that had a vertical spindle attachment installed. The main "tool" was their experience and skill. To put the parts( monoblock/barrel tubes, ribs) together, they sent them to the barrelmaker( rohermaker?) who had the appropriate equipment (oven). Even though my friend was qualified to fit the new barrels up, he usually called another friend in to do it. This fitter used mostly files and scrapers to fit the barrels in. He filed like a machine and worked right on top of thousands of dollars' worth of engraving without "missing a lick". His main equipment was also his skill.
If you take the project on and mess it up so badly that you can't sell the parts for scrap iron, you still would not have lost enough to outweigh the fun and experience you would have gained.
Mike