The point which they kept under wraps until about 40 mins in was plastic guns fail after one or two shots. I was slightly suspicious that they didn't test the rifle with a normal round. I suspect it would have failed after one round.

I took that cheap all plastic guns do fall apart but if you include a metal barrel and bits there's a good chance it will survive a bit.  Certainly they were able to fire a projectile that would have pretty much gone through a person.

What I wanted to know was what was he doing with all the crypto.  Using that to buy the metal parts or was he dealing in some manner as well?