"houshold tools and 20 minutes watching some teenager on youtube"
Yeah, if you want a gun that doesn't work or is actually an M16, that might work.
There's plenty of legitimate instruction for free online out there, with templates, step-by-step, the works. No need to low ball it.
Also, if you do it in 20 minutes with hand tools, it will probably not run. Use a drill press, at least. Please don't use it for milling, though; the side force will loosen the chuck and ruin either the gun or you when it goes flying.
TCB