Keep Americans Safe Act

This bill prohibits the possession, sale, or transfer of most large-capacity ammunition magazines (holding more than 15 rounds) for the general public, while exempting law enforcement officers (including campus security officers), retired officers, and certain licensed entities like nuclear facility security. It requires new magazines manufactured after enactment to have serial numbers and manufacturing dates, and allows federal grant funds to support buy-back programs for these devices. Existing owners of such magazines lawfully possessed before the law's enactment are exempt from the prohibition. The law applies to devices not already covered under current exemptions for law enforcement, nuclear security, and retired officers.