NOT KNOWN DETAILS ABOUT 9MM AR CONVERSION

Invented only two many years apart, the 9mm Luger/Parabellum and .forty five ACP are actually rivals on this planet of semi-auto pistols ever given that.Furthermore the round also performs nicely in PCCs including the Thompson, giving it legs beyond the restrictions of the pistol. Is a .45 ACP the only real pistol that should be in the collection?