http://www.mass.gov/dfwele/dfw/regulations/plain_language/hunting_shotguns.htm
Hunting with Shotguns and Shotshell Cartridges
It is lawful to hunt birds and mammals in Massachusetts with a shotgun of 10 gauge and smaller, and with any magazine capacity, EXCEPT:
1. The hunting of migratory game birds with a shotgun, the magazine of which has not been cut off or plugged with a 1-piece filler incapable of removal without disassembling the gun so as to reduce the capacity of the shotgun to not more than three cartridges at one time in the chamber and magazine combined, is PROHIBITED.
2. The use or possession of shotgun cartridges loaded with a rifled slug, single ball, buckshot of any size, air rifle shot, BB shot, or any other shot larger than #1 birdshot is PROHIBITED except: (a) on a target range during daylight hours, (b) for the hunting of deer during the period when it is lawful to hunt deer with a firearm, and (c) for the hunting of waterfowl, American coot, or coyote using B, BB, BBB, F, FF, T, or TT shot during the periods when it is lawful to hunt those species.
3. The use or possession of shotgun cartridges loaded with shot other than non-toxic shot is PROHIBITED for the hunting of waterfowl and American coot. Check the annual “Migratory Game Bird Abstracts” for the non-toxic shot types currently approved by the U.S. Fish and Wildlife Service.
4. The above prohibitions and restrictions also pertain to the use of muzzle-loading (smoothbore) shotguns, and the shot sizes which are allowed for use in them.
5. Check the firearms statutes pursuant to M.G.L. c. 140 and c. 269 for laws regarding the possession, carrying, and use of semiautomatic or other "large capacity" shotguns and feeding devices.
This is not the complete law and is subject to change. Refer to provisions of M.G.L. c. 131, § 66 and to several provision of the Code of Massachusetts Regulations, 321 CMR.
Regulations as of 10-05-07.