Lower reciever for pistol build?

[milemaker13]

Can you explain an AR pistol build? Is there a "special" lower reciever required? IE: I know that legally one can not simply assemble a pistol kit on top of an existing rifle lower.

Can an 80% lower be used legally on a pistol build in IL (not cook county).

Thanks in advance for advice on a topic that has likely been covered. I am looking at other threads too but sometimes asking is the best way to go. Thanks.

 

[KansasSasquatch]

On a Federal level as long as it was marked as an "other" on the Form 4473 and NOT as a rifle, it doesn't matter. And some will tell you that if the first upper you attach is a rifle upper then you can't legally ever switch it to a pistol. But it'd be hard for anyone to prove that you did that unless you're silly enough to do it in front of witnesses or somehow document it. I'm not suggesting you should put a pistol upper on a lower that you first attached a rifle upper to, just pointing out that it would be difficult to prove.

As far as being legal in the state of Illinois, I can't help you there. Illinois gun laws are so silly that I avoid the state, along with about 10 others.

 

[Theohazard]

On a Federal level as long as it was marked as an "other" on the Form 4473 and NOT as a rifle, it doesn't matter.

It doesn't matter what the dealer marked on the 4473. A lower receiver -- even one complete with a stock -- is still a receiver and not a pistol or a rifle since it doesn't have the required parts to fit the federal definition of a pistol or a rifle. What the dealer puts on the 4473 doesn't define what the firearm is. Remember, the 4473 is simply a transfer document, not a registration document.

If the dealer makes a mistake on the 4473 when selling a receiver, that doesn't change what the firearm is. Think of it this way: if someone at the DMV messes up and records your pickup truck as a motorcycle, that doesn't mean your pickup truck is now a motorcycle and you have to wear a helmet while driving, it simply means that a guy at the DMV messed up.

And some will tell you that if the first upper you attach is a rifle upper then you can't legally ever switch it to a pistol.

That person would be wrong because there's so such thing as a "rifle upper" since there's no length limit to a pistol under federal law.

 

[milemaker13]

How does that apply to an 80% lower?

 

[Theohazard]

To answer the OP's main question, under federal law if a receiver is first built as a rifle (a stock and a barrel longer than 16") then it can never be made into a pistol. However, if a receiver is built first as a pistol (no stock and it doesn't matter what the barrel length is) then it can always go back and forth between being a rifle or a pistol. Just make sure you never put a stock on it while it also has a sub-16" barrel since that would be an unregistered short barrel rifle. Check out ATF Ruling 2011-4 which clarified their position on the 1992 SCOTUS case US v. Thompson-Center Arms Co.

How does that apply to an 80% lower?

Doesn't make any difference whether we're talking about a normal lower or an 80% lower you build yourself, it's all the same. (Keep in mind I'm talking about federal law here, state and local laws might vary.)

 

[Wisco]

Good god, why do people keep perpetuating the 4473 “other” misinformation?

The manufacturer makes the gun. They say what it is. The FFL could say the receiver is actually a red-toed orangutan on the 4473 and it wouldn’t make it something else.

 

[dogtown tom]

Can you explain an AR pistol build?

In short, you build a firearm without a shoulder stock.
From ATF regulations:
Handgun. (a) Any firearm which has a short stock and is designed to be held and fired by the use of a single hand; and
(b) Any combination of parts from which a firearm described in paragraph (a) can be assembled.

That's FEDERAL, Illinois most likely has state requirements or definitions that differ.

Is there a "special" lower reciever required? IE: I know that legally one can not simply assemble a pistol kit on top of an existing rifle lower.

No.
A firearm frame or receiver is just a firearm frame or receiver until assembled as a handgun, long gun or other firearm. If the lower receiver was previously built first as a rifle, it cannot subsequently be remade or reassembled into a handgun.

Can an 80% lower be used legally on a pistol build in IL (not cook county).

No idea. Someone knowledgeable on gun laws in Illinois needs to chime in.

On a Federal level as long as it was marked as an "other" on the Form 4473 and NOT as a rifle, it doesn't matter.

Nope. Nope. Nope.
What was marked by the dealer on the Form 4473 doesn't affect what a frame or receiver is. If you were transferred an AR lower prior to November 2008, it was noted as "Handgun", "Long Gun" or "Both" because that was the only options on the 4473. Beginning that fall, ATF implemented a new 4473 that replaced "Both" with "Other firearm"....meaning a firearm that did not meet the definition of handgun or long gun. Beginning with that version of the 4473, the correct type of firearm to be marked for a frame or receiver is "Other firearm". If the dealer checks the wrong box it doesn't change what the firearm is. Even ten years later there are nitwit dealers who continue to check the wrong box. They do this because like a lot of people they don't bother to read the instructions.

And some will tell you that if the first upper you attach is a rifle upper then you can't legally ever switch it to a pistol. But it'd be hard for anyone to prove that you did that unless you're silly enough to do it in front of witnesses or somehow document it. I'm not suggesting you should put a pistol upper on a lower that you first attached a rifle upper to, just pointing out that it would be difficult to prove.

Nope. Nope. Nope.
There is no such beast as a "rifle upper" …...because Federal law does not restrict the length of a pistol barrel.
The thing to remember is SHOULDER STOCK/OAL/BBL LENGTH. If you first assemble a firearm with a shoulder stock and ANY length bbl....you create either a rifle or a short barreled rifle (requires an NFA tax stamp). The firearm can never be reassembled as a pistol because it was originally assembled as a rifle. "First a rifle, always a rifle".

If you build from a new lower receiver, you can build in any configuration you want FEDERALLY.....IL may ask you before you build what it is you are going to build.
If you buy a "complete lower" (one with a shoulder stock) be sure to remove the shoulder stock before assembling your pistol. If you build the firearm first as a pistol, it may be reassembled later as a rifle, the subsequently reassembled as a pistol.

 

[dogtown tom]

Good god, why do people keep perpetuating the 4473 “other” misinformation?

Mostly because they don't read the instructions on the 4473.

The manufacturer makes the gun. They say what it is.

No, ATF regulations define what a firearm is.
Several times I've run across manufacturers who wrongly identified the type of firearm they shipped.
Ex 1 a stripped lower that arrived with a Form 3. While it may have been an SBR at one time, it isn't if not in SBR configuration.
Ex 2 Colt inc shipping an AR without a shoulder stock....and they called it a rifle.

The FFL could say the receiver is actually a red-toed orangutan on the 4473 and it wouldn’t make it something else.

True.

 

[Hokie_PhD]

How does that apply to an 80% lower?

The 80% lower is a block of aluminum until it’s machined. Then it becomes a firearm. So until you start machining it it’s just like any other metal object in your home. But when it becomes a firearm you have to follow federal and state laws. Keep in mind some like CA have laws about serial numbers, registration, etc. so know the ones that apply to you and decide how to comply or if not what risks you’re will8mg to accept if you dont.