As a retired toolmaker - yes, yes I do. And a whole lot better than you. And I actually posses the tools, skills, knowledge required to manufacture a firearm completely from scratch - a lathe, mill, drill press and even a 3D printer. I suppose technically, I’ve built several “ghost guns” myself over the years. I sourced all the parts individually, including a stock blank, fitted them all together and built a fully functional firearm. They were all muzzle loading rifles, but they were real firearms. There is a vibrant, though niche industry, that caters to us “mountain folk” and our desire to touch the history. It was a truly fun and educational process that gave some real pride of craftsmanship in the end product.

The point still stands - full auto weapons are very uncommon, legal or otherwise, in public hands and you for sure won’t ever see such a thing as a full auto ghost gun on a public target range. Even cops don’t get to own full auto weapons in the US. At least not without jumping through some very, very, very difficult and expensive hoops that pretty much make it impossible.