Oh and on the same site.
5. States that Require Registration of Pre-Ban Assault Weapons, 50 Caliber Rifles, and/or Large Capacity Magazines: Six states (California, Connecticut, Hawaii, Maryland, New Jersey, and New York) have banned assault weapons,34 but allow continued possession of such weapons if they were lawfully owned on a specified date and are registered, except that grandfathered assault long guns in Maryland do not need to be registered. In California (the only state that currently bans the possession of 50 caliber rifles) any person who lawfully possessed a 50 caliber rifle before January 1, 2005, must have registered it no later than April 30, 2006 in order to retain possession of the firearm
5. States that Require Registration of Pre-Ban Assault Weapons, 50 Caliber Rifles, and/or Large Capacity Magazines: Six states (California, Connecticut, Hawaii, Maryland, New Jersey, and New York) have banned assault weapons,34 but allow continued possession of such weapons if they were lawfully owned on a specified date and are registered, except that grandfathered assault long guns in Maryland do not need to be registered. In California (the only state that currently bans the possession of 50 caliber rifles) any person who lawfully possessed a 50 caliber rifle before January 1, 2005, must have registered it no later than April 30, 2006 in order to retain possession of the firearm