Frames & Receivers

Chapter 135 (H.4885) – Frames & Receivers

Updated October 21, 2024

The following should not be taken as legal advice.


There is nothing in the new law that references 80% lowers, it simply refers to “unfinished” frames and receivers. (An unfinished AR receiver can be considered an unfinished machine gun!)


  • All frames and/or receivers (unfinished or otherwise) that could be considered a copy or duplicate of an enumerated Assault Weapon must have been lawfully possessed and registered in Massachusetts prior to July 20, 2016.
  • Any frames or receivers (unfinished or otherwise), not on the enumerated ban list, but meet the new features test must be possessed and registered in Massachusetts on or before August 1, 2024.
  • Private builds for any firearm that would fall under the new semi-automatic Assault Style Firearm definitions are prohibited after August 1, 2024
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