Final answer:
The sale of firearms or ammo from a Personal Firearms License must comply with all applicable laws and consider public safety, with the seller responsible for ensuring the buyer does not express a harmful intent.
Step-by-step explanation:
The discussion regarding when it is appropriate to sell firearms or ammo from a Personal Firearms (PF) License intersects with legal statutes, the interpretations of the Second Amendment, and public safety concerns. The legality of selling firearms from a Personal Firearms License is subject to various federal, state, and local laws which can differ significantly across jurisdictions. It is crucial for a person holding a PF License to understand the specific restrictions and obligations imposed by law, including background checks, waiting periods, and recording of sales. In the United States v. Miller and District of Columbia v. Heller cases, the Supreme Court acknowledged the right to keep and bear arms, but also the government's power to regulate arms in the interest of public safety. Therefore, selling firearms or ammo to someone who explicitly states harmful intent, as in the presented counter example, would not only be irresponsible but likely illegal under laws designed to prevent firearm violence.