Here is a classic traditional style break barrel 12 gauge shotgun built entirely from scratch using scrap steel plate and tubing which can be found at any decent hardware store. Using the the drawings here as a basis, the builder managed to produce something which functions well and is aesthetically close to a factory made piece. The building process is documented below.
“And it begins. I finally got hold of the 1/4 ” plate steel I needed to start cutting out the frame for my 12 gauge break barrel. There will be two pieces on each side of the internals. One piece on each side will have all the cut-outs for the moving parts, then the two outer layers will be solid except for the holes for pins and bolts. This will give it some weight to buffer some of the recoil.”
Hammer and trigger. A single spring powers both.
Using a drill and a jewelers saw to make cut outs in the side plates.
Everything temporarily bolted together with the stock.
Sanding the chamber in the steel tube barrel.
Trigger guard and latch fitted.
“Well, test fire of the 12 gauge went well. The only problem was the butt stock. If cracked on both sides. I kinda figured it might be a problem since I made it out of what I had on hand, which was a soft pine of some kind. But, all the hardware worked flawlessly! Now to locate a chunk of hardwood and start carving.”
“New stock update: Cut out two sections of the red oak and glued and clamped for 24 hours. Lined up all the holes and it looks like a good fit. I shortened the neck area where the stock meets the frame, and I’m reworking that connection area. I’m thinking of reinforcing that area with a wrap of brass.”
The finished gun: