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 an additional hollow point cavity. The locking groove was added to provide a controlled expansion quality while keeping the weight retention at an ideally high level. The new #9947 147gr JHP is heavy weight used to provide sub-sonic velocities from cartridges like the 9