It's interesting how thoroughly the guy was set up to cast aluminum- that's a well-built and well-used furnace, he's got a good design for the mold boxes, that looks like a professional crucible, etc. His machines are mid-grade imports, but quite serviceable, and so on.
And then he uses beer can metal for it all?
I'm going to have to assume he was using the beer cans just for the example of it- "Making a receiver out of beer cans" is more clickbait-worthy than "casting my own receiver out of aluminum".
Cans are generally 300-series aluminum, for the deep-drawing properties, with a 5000-series for the lid and tab. These can be cast- almost any aluminum can be cast- but it's a poor choice. (To say nothing of the fact you get almost nothing per can, due to slag losses- the guy likely melted down about a thousand cans to make that frame.)
It's possible the guy skipped showing us the step of adding silicon and copper to the melt, but the look of the cuts and the shrinkage at the gate suggest he didn't bother.
If he was doing that "for real", he'd have been much better off taking scrap aluminum that was already cast- car transmission cases, old lawnmower engines, etc.
But still, complaints aside, overall a cool video, and a couple of neat tricks in there. Still worth a watch.