Josh, the inventor of this fine piece of garage engineering writes:

Good evening all, and a happy early Thanksgiving.

I just wanted to share my abomination that I will attempt to test-fire tomorrow. This firearm is a rudimentary single-shot 20x102mm (20mm Vulcan) Destructive Device I built myself on an ATF Form 1. Every single part on here (minus the barrel (but including rear threading & muzzle brake), tripod, pintle, and traverse/elevation mechanism) I built myself, by hand. No CNC parts, nothing off-she-shelf except for a few bolts from the hardware store. The gun is not yet finished, but far enough along for it’s first prototype test-fire. I plan to do this tomorrow, at a family gathering out on the girlfriend’s property.