02/26/2020
United States v. Jimenez, 2016 WL3556810 (N.D. Cal). Only one part of an AR-15 receiver is not a firearm. This may have implications for anyone charged as a felon in possession of a firearm under federal law contrary to 18 U.S.C. 922 or possibly under Iowa State law code section 724.26 (no Iowa cases at this time). The ATF defines a firearm receiver in code section 921(a)(3) as, "that part of a firearm which provides housing for the hammer, bolt or breechlock, "and" firing mechanism, and which is usually threaded at its forward portion to receive the barrel."
However, if you possess only one part of an AR-15 receiver it does not meet the ATF definition because the AR-15 has upper and lower receivers. The upper receiver houses the bolt and enables insertion of the barrel. The lower receiver provides housing for the hammer and the firing mechanism.