A sporter stock is indeed the regular stock by another name as opposed to "tactical" stocks designed primarily for law enforcement needs such as pistol grip, folding stock etc.
Detachable magazine, yes, but no "Pistol Grip" if it's a "Thumbhole" stock and them you can still have the dreaded "Assault Bayonet Lug" or one of the other "high crime" features like a grenade launcher...