Sierra Bullets® has partnered with SIG Sauer® to bring you the ultimate defense bullet line delivering optimal weight retention and expansion at all effective distances combined with Sierra’s world renowned accuracy. The line features a stacked hollow point bullet design with additional hollow point cavity. For the #9924, #9925, #9465 and #9820 a cannelure halfway up the shank locks the jacket to the core ensuring maximum weight retention and terminal expansion. The #9924 was introduced in November 2015.