Pakistan paramilitary like Rangers use Sig 551 inducted in small numbers very recently. NSG used it and then upgraded to Sig 553 compact carbine. Aug A3 is damn old and clunky, it was good for a 1998 Black Ops unit. But today rifles half their size like Tavor, SCAR - H (I Love this one 7.62 x 51 + hk 416 like accuracy and rate of fire + 5.56 mode), REC - 7, make it look obsolete.