I thought that I'd seen everything, but if anyone wanted to build a Sig Sauer 220, 226, and 229 from an 80% frame and get the the necessary jigs to complete it, you can get them from Matrix Precision here: 220, 226, and 229 TOOLS AND JIGS — MATRIX PRECISION. For me, the price is a bit too...

I own quite a number of guns but recently I've been thinking about building one myself, to really customize it the way I want it. I've looked at several 2011 80% frames including the Black Mountains one. With the jigs available that cut the slide and barrel ramp I'm wondering how difficult it is...

This project is gong to be more fun than I thought it would be. Man, these frames are pretty raw. Not even the main spring housing area is cut. Anddd... I don't have a mill. Heh heh heh. I also got a cheap trigger and slid it in, turned out to be a tight, gritty fit. So that needs work too...

1911 Stealth Arms Phantom Jig https://uspatriotarmory.com/store/1911-Stealth-Arms-Phantom-Jig-p125659961 I just thought someone might need it. Looks like a pretty good deal to me. Your going to need multiple rail cutters for steel frames though.