The Supreme Court’s “common use” test has become the most practical shield the Second Amendment currently possesses, yet Charles Nichols is right to question whether it rests on solid originalist ground. By tying constitutional protection to how many Americans already own a particular firearm, the doctrine effectively converts popularity into a legal safe harbor—an approach that can safeguard the AR-15 today but could just as easily strip protection from a newly designed rifle tomorrow if regulators succeed in suppressing its market share first. That circularity exposes a deeper tension: the test may deliver wins in the short run, but it risks making the right to keep and bear arms contingent on contemporary consumer trends rather than on the historical understanding of the right itself.

For the broader 2A community, the stakes are both immediate and strategic. Litigators defending assault-weapon bans now face an uphill fight precisely because the AR-15 and its variants number in the millions; any ruling that severs “common use” from constitutional coverage would instantly imperil the single most popular center-fire rifle in America. At the same time, Nichols’s critique invites originalists to articulate a firmer historical baseline—perhaps rooted in the public understanding of 1791 or 1868—that does not hinge on sales figures. If that project succeeds, future protections could extend to arms that regulators have not yet allowed to become common, closing the regulatory “choke point” that currently lets officials limit a firearm’s popularity in order to limit its legality.