Ive never considered a pistol but this was from a friend who had sent a letter to BATF:
This refers to your letter of xxxxxxxxxx, in which you inquire
about the legality of manufacturing a handgun which utilizes a rifle
type receiver.
26 U.S.C. Chapter 53 # 5845(a)(4), the National Firearms Act (NFA),
defines the term "firearm" to include a weapon made from a rifle if
such weapon as modified has an overall length of less than 26 inches
or a barrel or barrels of less than 16 inches in length.
Utilizing the receiver of an existing rifle for the purposes of
manufacturing a handgun would constitute the making of a firearm as
defined above. Individuals desiring to make such a firearm must first
submit an ATF Form 1, Application To Make And Register a Firearm and
pay the applicable $200 making tax.
If an individual were to obtain a rifle type receiver that had not
previously been utilized in the assembly of a rifle, a handgun could be
made and not be subject to the provisions of the NFA. Verification
must be obtained from the manufacturer of the receiver to establish
its authenticity.
We trust the foregoing has been responsive to your inquiry. If we may
be of any further assistance, please contact us.
Sincerely your,
(signed)
M. Owen, Jr.
Chief, Firearms Technology Branch
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and there's this letter I've seen:
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So, from this Im assuming if the lower was registered originally as a Rifle, then Form 1 and $$$ is required to have it re-registered as a pistol lower. Does it require engraving on the lower to show as a pistol or ?? However, if you originally purchased the lower as a Pistol lower, then a Form 1 is Not required.
Is that correct? I might have to check into building one. cool looking pistol!