Although it confuses the hell out of them when you say "both" (I was buying .22LR).
Len, how would they even KNOW you're from MA unless you tell them? Do you have to show some kind of ID in NH to buy ammo?
Yes, you have to keep it real simple for the simpletons that work in places like Wal-Mart. Answers like "both" or "machine gun" cause a melt-down of both working brain-cells in most of their clerks.
Wal-Mart Corporate has directed all stores near the MA border to query ALL people for ID. When I show them my NH Permit it has a MA address on it, that's what befuddled the clerk (an older guy I've bought from before).
When I bought ammo at the Manchester, NH Wal-Mart, no questions and no ID asked for. It was far enough from the border that Corporate allows them to operate under NH rules (only if person looks <21). The cash register still queries the clerk (>21 yo and pistol/rifle), but he doesn't hassle the customer for proof unless he feels the person might be underage.