Bullets with great expansion like ballistic tips at high velocity from a powerful caliber will drop an animal in its tracks.

For example a 300win mag shooting a 150gr ballistic tip will drop an antelope in its tracks with a good double lung shot.

I see coyotes drop in their tracks all the time from the explosive varmint bullets out of a .223 or 22.250

Conversely controlled expansion bullets generally won' t drop an animal in its tracks unless the spine is hit.

I have never seen an elk drop in its tracks unless the spine was hit, but I' m sure others of you out there may have seen it.

The high shoulder shot which gets the spine will drop animals in their tracks.

These are methods you can use to drop animals in their tracks with some consistency, if you find that important.

Interesting info on the heart beat theory.