What is the lower? If you buy some sort of device that (I assume improves performance) for a semiautomatic, it can only function at 80%? Otherwise you can't sell it?
Not sure of your skill level, but if the idea of field stripping a gun is complicated, you may want to hold off on the 80% build. It's not hard, but a bit of common knowledge goes a long way.
On most guns the part with the serial number is considered the firearm. On rifles, it is usually the part with the receiver. Pistols, the frame. ARs are pretty unique on that they are comprised of an "upper" and a "lower". The lower is considered the gun and will have a serial number.
The receiver is what houses the trigger, firing pin, and mounts all the other major components. A 100% receiver is ready to build a gun. An 80% receiver needs some machine work to build a functioning gun. Since a gun is a collection of parts, the NFA defined the receiver as the specific part you buy that's regulated.
So the concept is you buy a receiver that's 80% complete and not ready to build a functional gun, finish the receiver by milling and shaping it, and then build your gun to avoid the paperwork hassle. https://i.imgur.com/8gVmvOA.jpg
Sort of. It's a NFA regulated item that requires a tax stamp from the ATF, but it's considered its own part.
If you want to buy a short-barrel rifle, you need a tax stamp for the gun. If you then want to add a suppressor, you need a second tax stamp for that.
As a side note, if you want to put a stock on your AR15 pistol, that's considered manufacturing a short-barrel rifle and needs a tax stamp.
An AR has a lower receiver.
An 80% lower is a chunk of metal that has been milled out to 80% complete.
The extra 20% has to be performed to complete to create a 100% lower receiver.
On the AR platform only the lower receiver is governed by law requiring an FFL to handle a buy/sell.
80% doesn't require paperwork since it's just an oddly shaped block of metal.
What is the lower? If you buy some sort of device that (I assume improves performance) for a semiautomatic, it can only function at 80%? Otherwise you can't sell it?
This is a great explanation. Thanks. How does one do the machining?
There are various methods
Not sure of your skill level, but if the idea of field stripping a gun is complicated, you may want to hold off on the 80% build. It's not hard, but a bit of common knowledge goes a long way.
The lower is what houses: the buffer tube, buffer spring assembly, buffer retaining spring, takedown pins, safety, grip, trigger, and bolt release.
The upper houses: the charging handle, bolt, barrel, gas tube, gas block, the sights, and the handguard.
I hope that this helps.
On most guns the part with the serial number is considered the firearm. On rifles, it is usually the part with the receiver. Pistols, the frame. ARs are pretty unique on that they are comprised of an "upper" and a "lower". The lower is considered the gun and will have a serial number.
The receiver is what houses the trigger, firing pin, and mounts all the other major components. A 100% receiver is ready to build a gun. An 80% receiver needs some machine work to build a functioning gun. Since a gun is a collection of parts, the NFA defined the receiver as the specific part you buy that's regulated.
So the concept is you buy a receiver that's 80% complete and not ready to build a functional gun, finish the receiver by milling and shaping it, and then build your gun to avoid the paperwork hassle.
https://i.imgur.com/8gVmvOA.jpg
Dumb it down a bit for me, if you could, please.
See my above comment.
ELI4
the supressor is also considered a firearm by the law
Sort of. It's a NFA regulated item that requires a tax stamp from the ATF, but it's considered its own part.
If you want to buy a short-barrel rifle, you need a tax stamp for the gun. If you then want to add a suppressor, you need a second tax stamp for that.
As a side note, if you want to put a stock on your AR15 pistol, that's considered manufacturing a short-barrel rifle and needs a tax stamp.