Mass. Gen. Laws ch. 140 § 128A
The provisions of section one hundred and twenty-eight shall not apply to any person who, without being licensed as provided in section one hundred and twenty-two, sells or transfers a firearm, rifle or shotgun to a person licensed under said section one hundred and twenty-two, or to a federally licensed firearms dealer or to a federal, state or local historical society, museum or institutional collection open to the public. The provisions of section one hundred and twenty-eight shall not apply to any resident of the commonwealth who, without being licensed as provided in section one hundred and twenty-two, sells or transfers to other than a federally licensed firearms dealer or organization named above not more than four firearms, including rifles and shotguns in any one calendar year; provided, however, that the seller has a firearm identification card or a license to carry firearms, is an exempt person under the conditions of clauses (n), (o), (r) and (s) of the fourth paragraph of section one hundred and twenty-nine C, or is permitted to transfer ownership under the conditions of section one hundred and twenty-nine D and the purchaser has, in the case of sale or transfer of a firearm, a permit to purchase issued under the provisions of section one hundred and thirty-one A and a firearm identification card issued under section one hundred and twenty-nine B, or has such permit to purchase and is an exempt person under the provisions of section one hundred and twenty-nine C, or has been issued a license to carry firearms under the provisions of section one hundred and thirty, or in the case of sale or transfer of a rifle or shotgun, the purchaser has a firearm identification card or a license to carry firearms or is an exempt person as hereinbefore stated. Any sale or transfer conducted pursuant to this section shall comply with section 131E and shall, prior to or at the point of sale, be conducted over a real time web portal developed by the department of criminal justice information services. The department of criminal justice information services shall require each person selling or transferring a firearm, shotgun or rifle pursuant to this section to electronically provide, though the portal, such information as is determined to be necessary to verify the identification of the seller and purchaser and ensure that the sale or transfer complies with this section. Upon submission of the required information, the portal shall automatically review such information and display a message indicating whether the seller may proceed with the sale or transfer and shall provide any further instructions for the seller as determined to be necessary by the department of criminal justice information services. The department of criminal justice information services shall keep a record of any sale or transfer conducted pursuant to this section and shall provide the seller and purchaser with verification of such sale or transfer.
Mass. Gen. Laws ch. 140, § 128A