Complex sentence: Many pistol and rifle magazines classified by gun control laws as "high capacity" are actually the factory standard magazines originally designed for use with their respective firearms and reduced capacity magazines were later created in response to enactment of the bans.
Split into simpler sentences: Many pistol and rifle magazines classified by gun control laws as "high capacity" are the factory standard magazines originally designed for use with their respective firearms. Reduced capacity magazines were created in response to enactment of the bans.