Well enough to hit any major organ. The spleen shot is overrated however. We shoot center mass because its loaded with nerves, vessels and organs. It makes it a high probability shot. If you take long enough to aim to hit the heart you are not going to survive. Lead on COM preferably with something that will penetrate through and through from any angle is your best bet.
That's why the shot placement people always crack me up. You don't place shots in combat you train and train and when combat happens you fire. If you cant draw and fire and hit COM with no sights under crappy conditions you need to train more.