THIS.
And, if purchasing in Massachusetts, you're doing so in a state that is already demonstrably hostile towards gun owners. If they're not PotBuyers ⨝ (LTC ∪ FID) at the moment, what makes you think they won't in the future? In fact, if federal law changes, I wouldn't put it past them to pass a state disqualifier.
there is already a time tested strategy for such laws:
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