From what I understand, given IANAL and don’t own one:
Background checks: Yes
Waiting period: no
Crimes: any felony, or domestic violence charges
Gun shows: AFAIK that’s never actually been true
Other: Probably 16 or 18+ but I don’t think there is anything federal
Explosives: lots of paper, similar to an automatic firearm
99% of the what I’ve seen is more deadly to the user than to anyone on the receiving end. You’d really be better off with a pipe pistol or shotgun.
But yeah, almost anything could be dangerous depending on how it’s applied.
Just export controls though?
Don’t they effectively do all of those things already? Maybe they have someone else produce or run them, but they already seem to make all of those.
I know you can clean tpu with diluted bleach, did you try anything that harsh?
I’m guessing you could clear coat it to keep it cleaner for longer
A website costs money to register, develop, operate, and maintain.
Looked into the ones you mentioned, both require non-printed parts.
Those are better than what I had seen, but aren’t even on the same scale as what someone can make with a mil or a lathe casually in a couple days