>>80347
Ammunition is extremely easy to make. The four main components are the actual bullet, the powder, the casing, and the primer. Shotguns have a "cup" to prevent damage to your barrel, but that's as "more complicated" as it gets. Rifles have rifling in the barrels which adds a little more complexity in regards to ammo sizing, but otherwise they effectively function the same as a shotgun and revolvers have huge tolerances as well for launching shit you aren't supposed to from them. With the exception of powder, every component of a round of ammunition is reusable/recyclable. With the exception of primers, every piece in making ammunition can be produced at home with unrelated goods and re-purposed for firearms. Ammunition is like meth- you can make it from just about anything if you're willing to put in the time and energy to convert it into a proper form. And like homemade meth, homemade ammunition will eat half your face, but that's a different story. Now, I wouldn't recommend recycling primers as you have to be an idiot or desperate to do so, but those are potentially the "hardest" part to acquire in a gun ban zone since they don't really serve many non-gun purposes. Mechanical primers are a thing, but then you're probably dealing with black powder which is its own mess.
>>80348
The "power" (by which I assume they mean "pressure") is a lesser issue in black powder compared to the energy density which makes it unstable/unusable with more armor-piercing rounds. You really don't want squib loads from your pressure systems not being strong enough.
https://www.liveleak.com/view?t=598_1334471467
>>80352
I'm sure they'll make exceptions for businesses and if you have a special license that lets them search your computer at the drop of a dime without any warning. I actually can't find anything on 3D printers being illegal.