>Am I cool to buy this and transport into Mass
Generally speaking, one requires a license to possess a gun or ammo in Mass. There are exceptions for sworn LE on duty, and for participation in a formal competition [not just dirt shooting]. So, no dice, and that's without getting into the AG's fuckery on re-interpreting the AWB.
>can I give this as a gift to someone IN Mass and leave it there?
Private transaction involving a gun across state lines? Generally illegal, friend.
Those were the questions you asked initially.
Getting into the fuckery from the Attorney General - on 7/20/2016, Healey's office announced that *all* AK / AR / similar rifles which were copies of guns banned by the state AWB* were illegal to possess. That anyone currently in possession was a felon. That it wasn't possible to comply with the ban by removing prohibited features. But that the AG's office wasn't interested in prosecuting all these new felons.
Sales of AR / AK type guns has essentially stopped. The only known legit avenue for these types of guns involves new manufacture fixed magazine lowers. JC Arms won a lawsuit over these, and we have a court ruling that fixed mag lowers [manufactured as fixed, not with a bullet button installed after the fact] are legal.
Honestly, it gets worse, but that should address most of what you're asking.
If you want to get your friend a rifle, have that person get their license and buy a gun in state. MUCH simpler, quicker, and cleaner for all involved. Just gift them some money if you need to.
*state level version of the federal AWB of 1994, but without sunset provision