It’s not as easy as getting a drill and a jig.
this looks like a better option:
http://www.80percentarms.com/collections/lower-jigs
I've never seen one of those before. That is pretty neat.
Still, all of that is a far cry from actually building a weapon from scratch. My long-term objective is to scratch build everything, including the barrel. It won't be an AR15 since that is actually way beyond a scratch build in a manual shop.