right tools is a big one. I find it odd that the people accused of perpetrating the police action are always described as low income, uneducated thugs, yet they have the know how and access to a machine shop to create illegal weapons.
I doubt that the 'low income, uneducated thugs' with the guns are the ones retooling them. They'd buy the guns action-ready from whoever it is who makes money from selling illegal weapons.
Note, however, that I've never really had any connection to gang or gun culture, so this is all my ignorant speculation.