someone school me on zip gun vs 80% lowers

[Sir Stunna Lot]

im assuming building an AR pistol/rifle from an 80% lower isnt considered building a zip gun.

but can someone explain to me why?
thanks

[the86d]

It is a "replica" of a mass-produced model firearm, and looks like a gun familiar to the officer that could possibly run you in... rather than something home-made for conceiled-carry-murder. (Apparently this is debatable, as many anti-gun Communists [AKA whiny-pinko-commie-hippy-bastard] see anything that isn't hot-pink and single shot, or bolt action as an assault weapon[, even semi-automatic pistols? ]. If it is black, they don't like it. This is due to a lack knowledge about something they want to ban.) Apparently in their eyes: pistol grips, compensators, and adjustable stocks on rifles are NOT for firearm-control, they are only used for homicide.

It assumed to rifled barrel (as I assume you will be putting standard parts on top). AFAIK to qualify for a Zip-Gun the barrel must be a smooth-bore, AND fire a fixed cartridge.

Make sure to put a bullet button on it.

[ClarenceBoddicker]

The CA "zip gun" law is modeled from the Fed 1934 NFA, like many CA anti-gun laws are. Check out AOW in the NFA.

[Purple K]

Building a rifle or pistol based on an 80% receiver is legal as long as its configured properly as to barrel length, overall length, etc. A "zip gun" by definition doesn't typically meet those dimensional requirements.

[Sir Stunna Lot]

thank you very much gentlemen (and ladies?), makes sense to me now

[Smokeybehr]

IIRC, it also has something to do with being immediately recognizable as a firearm, too. Handguns and long guns generally have the same general appearance, while zip guns and some AOWs DON'T look like firearms.

A thought: what about the Liberator pistol that was dropped across Europe during WWII to the resistance forces? It's a single shot .45 that is made out of sheet metal and has a smooth bore.