Built some from kits, but I decided to build one from whatever I had lying around.
Here's a short video of the action, and the nearly finished product - still have to sight it in and file down the front blade.
The barrel is a Colerain 36 twist I had made for maxiballs. It's a 54 caliber.
https://www.youtube.com/watch?v=GJCFZMcW8Dc
Attachment 272873