Machining an 80% AR receiver can be a fairly involved process, depending on your own availability of tools and machining experience. YouTuber GunCraft101 took making an AR lower more than a bit further, and sand cast and machined his own receiver, in the process using over 200 aluminum beverage cans. Noting that aluminum cans are typically a blend of magnesium and aluminum, with other trace metals, various industrial chemicals and additives, and a different grade of aluminum than those used for typical AR receivers, this is best observed as a curiosity rather than emulated. All the same, it really shows that a bit of technical know how, experimentation, and effort can combine to form some pretty cool results.
