Like many of us who are a day or two over 40, I also bought one of these pistols, in 1970 or so. I bought it from EMF when they were just starting out - paid $17.50 plus I believe 1.50 shipping. Under twenty dollars total. Didn't get much use out of it because the frizzen was way soft. A few years ago, I casehardened the frizzen and have shot it a few times. I can't hit much with a pistol and this one is a smoothbore. Without sights. So it just didn't see much use.
I've heard the reports that some breechplugs were welded in or maybe only pressed in. Never gave it too much thought until I read this thread. So today I decided to find out for myself if this pistol is safe to shoot. Only waited forty-some years!
I took the barrel out of the stock. That so-called "blind pin" turned out to be a four penny nail! Remember, these guns were not expensive. The breechplug/tang area looked similar to the picture in WRussell's post. It's just an opinion, but I feel that the welding is to attach the tang. Just a feeling. I screwed and strapped the barrel to a board and headed out into the country.
After checking with a DGW catalog, I selected the Definitive Proof Load for a 15 gauge (.677) bore. I used 165 grains of GOEX FFFg powder. The chart called for 656 grains of lead. Fourteen single-ought buck weighed 658 grains. Close enough. I inserted a length of firecracker fuse through the touch-hole, with about four inched protruding. Then the powder, dry newspaper wadding, the buckshot and more newspaper - wet this time. Tamped it all down well, put the whole thing behind a tree, lit the fuse and got behind a friendly three-foot thick maple.
After five seconds or so, the thing cut loose. What a bellow! But I'm pleased to say that everything held together just fine. Brought it home, cleaned it thouroughly and re-assembled the pistol.
I probably still won't shoot it too often. But I won't worry when I do, using 30 grains of powder and a 430 grain ball. And that certainly does not mean that all pistols of this type/era are safe. But I'm satisfied that mine is.
Safe shooting,
Sneezy