Terminal ballistics are important. I've seen a deer shot right through the heart run for 150 yards. The bullet used did not expand properly, so there was very little energy transfer. What stopped him was blood loss and a deer can travel a long way before they bleed out most of the time. What you want is a combination of good energy transfer to drop them and then massive blood loss to keep them there.I've seen big deer run a quarter mile after being hit with a 30oughtadropem6 and losing what looked like a 5 gallon bucket of blood. But I've seen much lesser calibers drop em without so much as a wiggle.Realizing this isn't an effective caliber thread, I have to side with Jack O'conner. It has yet to fail me.