[rtkwe]

No it's because the lower is legally the gun, because it has the trigger and hammer assembly in it. The whole rest of the upper half of the gun can be ordered online and shipped right to your house because it isn't legally a gun or the critical components.

[6nf]

Very different in Australia where every part of the gun is restricted. You can’t buy a single gun part and you certainly can’t buy ammunition without a license.