I have found the Nosler Ballistic tip at high speed to accomplish this. 120 gr 6.5MM and the 150 gr 7MM at 2800+fps.

On animals the size of big whitetails or muleys, it's normally pretty easy to drop them straight down. A lot of people are using a fairly heavy-jacketed premium bullet on deer and they always run 50 yards and fall over. With a high lung shot and a standard Sierra or Hornady from a ..270, 7mm, etc., most fall in a heap. The 55gr. .220 Swift or .22-250 will do the same thing with a high lung broadside shot. Elk, however are another story and I think it's going to take more gun to get a high percentage of them dropping straight down. Just realize that you can't have sudden kills with a bullet that will penetrate the length of an elk. If someone knows where to get this bullet, I'm a buyer for several boxes, although the Nosler partition is as close as I've ever got.

In his response Ray Atchenson makes the comment about the lungs being inflated or not and resulting different reactions. I know of three separate instances of a whitetail being hit with an arrow on a broadside shot where the entry and exit wounds were in front of the the diaphram and the liver and intestines hit instead of the lungs. All three ending in fatal albeit long tracking next day recoveries. Obviously the hit was on an exhail with the lungs deflated and the diaphram moved all the way forward, allowing the liver and stomach to fill the void. Other hits in the same locations resulted in two lungs and quick kills. I would imagine the same can happen with a similar hit and a heavy slow moving round from a rifle.

I used to shoot low, most times taking out the heart, and game was not reacting or charged into the bush to fall a few yards away.I met someone at the shooting range who suggested I shoot higher, above midline.Ever since, they have been dropping in their tracks.I think this is because of the high pressure generated near the spine,or high pressure generated everywere.

shootaway you got it ,it is no mystery.All this discussion about something that is almost automatic with a high powered gun.Hit high,you don t have to hit the spine and the shock will do the rest.I wonder how many people the policeman had seen shot at close range in the sternum from a 30 06.It would problably break a persons neck,yet he is probably right about instant kills,but enough force wil totally paralyse a deer for the 8 to 10 seconds it takes for brain death.Now I don t have as much experience as many at this site,so I would like to ask a question?How many people have shot a deer high in the shoulder bone with a 30 06 or better inside 150 yards and not have the deer drop.I ve personally never heard of them not dropping.Myself as well as 8 hunting brothers.