Ammunition and magazine laws in Massachusetts

(f) Prior to any transfer, a licensee shall verify the status of any license, card, permit or exemption documentation including a verification that the person presenting the license, card, permit or documentation is the lawful holder thereof. No transfer of any firearm or ammunition shall be made to any person not in possession of the required license, card, permit or exemption documentation at the time of the transaction.
(k) No licensee shall fill an order for any firearm or ammunition received by mail, facsimile, telephone, internet or other telecommunication unless such transaction includes the in-person presentation of the required license, card, permit or documentation as required herein prior to any sale, delivery or any form of transfer or possession. Transactions between federally licensed dealers shall be exempt from this subsection.
(l) Licensees shall ensure that all firearms and ammunition shall be unloaded when delivered and that delivery shall be only made to a person with the proper license card or permit or exemption to possess the firearms or ammunition included in the delivery.

''Large capacity feeding device'', (i) a fixed or detachable magazine, belt, drum, feed strip or similar device that has a capacity of, or that can be readily converted to accept, more than 10 rounds of ammunition or more than 5 shotgun shells; or (ii) any part or combination of parts from which a device can be assembled if those parts are in the possession or control of the same person; provided, however, that ''large capacity feeding device'' shall not include: (a) any device that has been permanently altered so that it cannot accommodate more than 10 rounds of ammunition or more than 5 shotgun shells; (b) an attached tubular device designed to accept and capable of operating only with.22 caliber rimfire ammunition; or (c) a tubular magazine that is contained in a lever-action firearm or on a pump shotgun.

(x)(1) It shall be unlawful for a person to sell, deliver, or otherwise transfer to a person who the transferor knows or has reasonable cause to believe is a juvenile—
(A) a handgun; or
(B) ammunition that is suitable for use only in a handgun.
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(5) For purposes of this subsection, the term "juvenile" means a person who is less than 18 years of age.

Small Arms Ammunition: Ammunition is classified as a Division 1.1, 1.2, 1.3, or 1.4 explosive, depending on the degree of hazard. Ammunition that is regulated as a Class 1 explosive and designed to be fired from a pistol, revolver, rifle, or shotgun, as well as associated primers and blank cartridges (including those designed for tools) and propellant powder for use in any firearm, is prohibited from mailing.
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Shotgun Hulls, Empty Casings, Nonmetallic Shotgun Hulls, or Casings Without Primers: These articles are not classified as explosives or hazardous materials under 49 CFR and, therefore, are mailable, subject to the applicable mailing rules (refer to 224).