I didn't mean the transaction. Further from the border you may or may not be asked. I been asked and not asked for MA id. The further north you go, the less interested the stores seem. (this is a GOOD thing IMO)
It's when he goes home. The OP never stated he's licensed in MA, although it is a reasonable assumption. If he doesn't have a MA FID/LTC, he'd be in possession of ammunition without a license, if he brings it home.