1. Commercial buffer tube.
2. Not knowing the parts freaking names. (It's a freaking buffer detent, a detent spring, a receiver end-plate, castle nut - IT'S NOT THAT DAMN COMPLICATED!!!)
3. Unstaked Castle Nut.
4. A screwdriver?!? Really...
I have to stop there, at 7:55 I had to shut it down. Was getting too damn irritated to watch anymore.
I just watched most of that and actually feel like I may have lost some brain cells.
I kept waiting for him to stick the screwdriver in his eye but that never happened.
Maybe next time...