I started with a Pardus shotgun I bought for $89. It's a Turkish folder with an internal hammer. I also have a .357 mag barrel from a Timberwolf rifle that madmathemagician on the GBO forum generously gave me for the cost of shipping.
Link to donor shotgun:
https://www.centerfireguns.com/i-o-s...-pard0001.html
I decided to start by prepping the receiver. First up was a trigger job. Two pins hold the trigger group to the receiver and then three more hold the hammer, sear, and trigger.
Here is how they interact:
I polished the mating surfaces and SLIGHTLY flattened out the notch in the hammer so that pulling the trigger doesn't cock the hammer further. I also swapped the sear spring for one with about half of the strength. The trigger is now about 4 lbs, smooth, but still a little creep. I'm going to leave it there and err on the side of safety.
Polished parts:
Next, I had to do something about that big shotgun firing pin. So I drilled and tapped the receiver for a 6-48 screw:
Then drilled the screw lengthwise with a .070" bit:
Used JBweld to secure it in place:
Cut it flush and touched it up with some cold blue:
Chucked the firing pin in the mill and used a dremel to grind it down. (It's a little uneven - I may have to turn one on the lathe.)
It has a max of .068" protrusion, so I may need to trim it back.
Next up: Barrel and extractor.