Assemble. To fit together a firearm's component parts; provided, however, that "assemble" shall not include firearms reassembly, repair of the fitting of special barrels, stocks, or trigger mechanisms to firearms.

Conspicuously. Placed in such a manner as to be wholly unobstructed from plain view.

Firearm. A stun gun, pistol, revolver, rifle, shotgun, sawed-off shotgun, large capacity firearm, assault-style firearm and machine gun, loaded or unloaded, which is designed to or may readily be converted to expel a shot or bullet; the frame or receiver of any such firearm or the unfinished frame or receiver of any such firearm; provided, however, that "firearm" shall not include any antique firearm or permanently inoperable firearms defined in M.G.L. c. 140, § 121.

Frame. The part of a pistol or revolver that provides housing or a structure for the component designed to hold back the hammer, striker, bolt or similar primary energized component prior to initiation of the firing sequence, even if pins or other attachments are required to connect such component to the housing or structure. Any such part that is identified with an importer or manufacturer serial number shall be presumed, absent an official determination by the Bureau of Alcohol, Tobacco, Firearms and Explosives in the United States Department of Justice or other reliable evidence to the contrary to be the frame of the firearm.

Individual. A natural person.

Manufacture. To fabricate, make, form, produce or construct, by manual labor or by machinery, a firearm; provided, however, that "manufacture" shall not include firearm reassembly, firearm repair or the making or fitting of special barrels, stocks or trigger mechanisms to firearms.

Massachusetts Instant Record Check System (MIRCS). The automated system (and any successor system) owned and maintained by the DCJIS that provides on-line firearms licensing by licensing authorities and on-line reporting of gun transactions by gun dealers.

MIRCS Firearms Licensing Portal (MIRCS Portal). The web-based system that allows users to electronically submit information to and/or request information from the DCJIS via the MIRCS. The MIRCS portal may be used to submit a firearms license application, check the status of a firearms license application, report a name or address change, obtain a firearms license PIN, request a unique firearms serial number, and register a firearm.

Permanently Embedded. Applied in such a way that cannot be easily or readily removed without destroying the part to which it is applied.

Privately Made Firearm. A firearm manufactured or assembled by an individual who is not a licensed manufacturer; provided however, that "privately made firearm" shall not include firearms manufactured or assembled by person licensed under M.G.L. c. 140, § 122 in the course of their business activities.

Receiver. The part of a rifle or shotgun that provides housing or a structure for the primary component designed to block or seal the breech prior to initiation of the firing sequence, even if pins or other attachments are required to connect such component to the housing or structure. Any such part that is identified with an importer or manufacturer serial number shall be presumed, absent an official determination by the Bureau of Alcohol, Tobacco, Firearms and Explosives in the United States Department of Justice or other reliable evidence to the contrary, to be the receiver of the firearm.

Requestor. Individual, entity, or manufacturer requesting a unique serial number from DCJIS via the MIRCS portal.

Serialization. The process of conspicuously engraving, casting or otherwise permanently embedding a unique serial number on a firearm.

Unfinished Frame or Receiver. A forging, casting, printing, extrusion, machined body or similar item that:

1. (a) has reached a stage in manufacture when it may readily be completed or assembled to function as a frame or receiver; or
2. (b) is marketed or sold to the public to become or be used as the frame or receiver of a functional firearm once completed or assembled; provided, however, that "unfinished frame or receiver" shall not include a component designed and intended for use in an antique firearm.

Valid Serial Number. An identifying number that has been:

1. (a) placed on a firearm by a federal licensee authorized to serialize firearms or pursuant to the laws of any state or 26 U.S.C. 5842 and the regulations promulgated thereunder; or
2. (b) a serial number issued by the director of the Bureau of Alcohol, Tobacco, Firearms and Explosives in the United States Department of Justice or the DCJIS.