Commonwealth v. Conelius
This is where I was getting it from. Maybe I misunderstood the implications. Let me know and I can correct my previous post.
Edited to add: I'm NOT a lawyer, but
this would appear to be the applicable section:
"This court concluded that new residents of the Commonwealth and certain returning residents, by satisfying the firearm identification card exception set forth in G. L. c. 140, § 129C(j), thereby satisfy the firearm possession exception set forth in G. L c.269, § 10(a)(4), for a limited period of time, without also having to comply with the provisions of G. L. c. 140, § 131G (relating to nonresidents) [416-419]; however, satisfaction of the firearm identification card exception in § 129C(j) does not provide a defense to a charge of violating G. L c. 269, § 10(m), which prohibits the possession of a large capacity weapon without a license [419-420]."