A bill to penalize the possession of certain firearms which are in effect machine guns, and for other purposes.

Makes it a Federal criminal offense for any person to possess a readily convertible firearm (a machine gun). Provides for a fine of not more than $250,000 or imprisonment for not more than ten years or both. Establishes an exception regarding the use of such firearm by the United States or by a State or local agency. Allows for a 90-day transition period before the prohibition takes effect.

Authorizes the Secretary of the Treasury to purchase during the applicable transition period any such firearm at a price not greater than fair market value. Requires the Secretary to notify persons possessing such firearms of the provisions of this Act.