A friend went to the SW Indoor IDPA match recently and said leaving from MA was a horror. The TSA and local law made him prove that he legally had the right to possess each gun (he took copies of the fed law and local law which said that if you were there for a sanctioned match it was legal). It took forever.
No expert on MA or Boston but is it legal to have a handgun in Boston without some paperwork. I won't trust the fed law to protect you from the locals.
But, what do I know - some MA folks can help you out.
BTW, don't MA bash folks - just answer the question.