I literally quoted it. The rule (if adopted) verbatim says that in an AR-15 the lower receiver is the "receiver". They would have to remove that paragraph from the rule to make any other part of an AR-15 the "receiver". The way you do that (remove a paragraph) is the rulemaking process. (notice of proposed rule change, public comment, final rule change, publishing in federal register)
That illustration is not the rule. It is specifically referenced as one of several "
nonexclusive examples that illustrate the definition."
The relevant portion of the actual definition is:
A part of a firearm that, when the complete weapon is assembled, is visible from the exterior and provides housing or a structure designed to hold or integrate one or more fire control components, even if pins or other attachments are required to connect those components to the housing or structure. Any such part identified with a serial number shall be presumed, absent an official determination by the Director or other reliable evidence to the contrary, to be a frame or receiver. For purposes of this definition, the term “fire control component” means a component necessary for the firearm to initiate, complete, or continue the firing sequence, including any of the following: hammer, bolt, bolt carrier, breechblock, cylinder, trigger mechanism, firing pin, striker, or slide rails.
[...]
(b) Split or modular frame or receiver. (1) In the case of a firearm with more than one part that provides housing or a structure designed to hold or integrate one or more fire control or essential internal components (e.g., a split frame with upper assembly
and lower assembly as in many semiautomatic rifles, upper slide assembly and lower grip module as in many semiautomatic handguns, or multiple silencer modular pieces), the Director may determine whether a specific part or parts of a weapon is the frame or receiver, which may include an internal frame or chassis at least partially exposed to the exterior to allow identification. In making this determination, the Director will consider the following factors, with no single factor being controlling:
(i) Which component the manufacturer intended to be the frame or receiver;
(ii) Which component the firearms industry commonly considers to be the frame or receiver with respect to the same or similar firearms;
(iii) How the component fits within the overall design of the firearm when assembled;
(iv) The design and function of the fire control components to be housed or integrated;
(v) Whether the component may permanently, conspicuously, and legibly be identified with a serial number and other markings in a manner not susceptible of being readily obliterated, altered, or removed;
(vi) Whether classifying the particular component is consistent with the legislative intent of the Act and this part; and
(vii) Whether classifying the component as the frame or receiver is consistent with ATF’s prior classifications.
This proposed rule gives the ATF the independent authority to determine what component
or components are receivers so long as they meet the very broad definition of:
1. Being visible from the exterior
2. Holding or integrating any fire control components
This clearly could be used to identify an upper receiver as a firearm receiver. As you point out, there is also nothing precluding multiple registered components on an assembled firearm.
To be fair to you, the proposal also says they aren't trying to change existing determinations and the rule implies deference to previous determinations as well as industry and manufacturer acceptance, however the stated intent of the rule does not necessarily impact the rule itself. It clearly places the ATF in the position of making receiver determinations based on a broad definition which could easily apply to multiple components without going through the rulemaking process again.
Also probably good to keep in mind that for the past 50 or so years we've relied on the existing definition - despite (per the ATF themselves in this proposed change) that definition not literally applying to most modern firearms. Regardless, they have enforced it as though it did. Only when pressed in court did they back down, and then only by stopping prosecution of individual cases. You seem to think that if we broaden the definition the ATF will suddenly decide to limit themselves and not continue their overreach. I don't have the same faith in that agency.
I think a lot of people don't understand what they did with the bump stock thing (which, you will recall, lost in court).
Are you under the impression that the bumpstock ban has been overturned? Also, as I recall last time it came up you defended the bumpstock ban as totally kosher. Have you changed your position on that as well? We've discussed it at some length before, but if there's something you think I don't understand about it I'd love to correct my lack of understanding.
If they had a CFR that literally said "A bump stock is not a machine gun" then they couldn't have made it one with a determination letter.
For the past 50 years they made AR lowers into receivers despite the CFR that literally said they weren't. So...
This is only the proposed rule change, so it may change before final adoption, but the rule, as proposed explicitly says the lower of an AR is THE[/i] receiver for the purposes of federal law.
Interestingly, the proposed rule states:
The following is a nonexclusive list of such weapons and the specific part identified as the frame or receiver as they existed on [date of publication of the final rule]:
That seems to imply that these determinations could readily change and considering that based on the rule the ATF can independently define what a receiver is within the broad limits of the rule I don't see this as formally limiting the ATF in the way you assume it will.