The gun comes with 3 magazines already, that gives you 51 loaded rounds before you ever slip one into the gun, why would you need an extended magazine? Seriously it's balanced perfectly the way it is and adding more rounds will just make a clumsy out of balance clunker out of a beautiful gun.
Just dos centavos from an old dinosaur who thinks they did the job right the first time.
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters.