Building an AR Lower from Bolted Together Flat Pieces of Metal

While manufacturing an AR lower on a computer numeric control (CnC) machine is possible most people still lack a CnC machine. Fortunately Zerg539 alerted me to a forum post detailing how an AR lower can be manufactured from bolted together flat pieces of metal, which can be done with tools that are more commonly available than CnC machines. Detailed blueprints can be found here [PDF].

Blueprints like this make implementing Plan B even easier. Decentralized manufacturers could pull together the tools necessary to cut and drill flat pieces of metal easier than they could pull together resources to acquire a CnC machine. Furthermore the tooling for an AR lower build from flat pieces of metal could be spread out between multiple locations which would make shutting down a manufacturing ring even more difficult. I believe manufacturing an AR from flat pieces of metal would also be much cheaper and therefore AR pattern rifles could be made even more readily available to those with few funds.