The Immigrant Legal Resource Center has a declaration from a California attorney establishing that in San Bernardino County, the prosecutor prosecuted a felon in possession of two antique/replica civil war era guns, under Penal Code 12021(a). This is the same definition of firearm that is used in a number of California firearms statutes. This declaration establishes not only that there is a reasonable probability that the prosecutors in California prosecute antique firearms under the California definition of firearms, but that they have actually done so. Thanks to Daniel G. Degriselles.