July 17 (Reuters) - A federal appeals court on Friday ruled that New Jersey's assault-weapons law barring the possession of AR-15 semi-automatic rifles and large capacity magazines containing more than 10 rounds of ammunition is unconstitutional. The ruling by the Philadelphia-based 3rd U.S. Circuit Court of Appeals marked the first time a federal appeals court had ruled that a state's assault weapons ban violated the U.S. Constitution's Second Amendment by burdening the right to keep and bear arms for self-defense.