What do you suppose it is like? Is loss of consciousness or death instantaneous? Does the condemned even hear the gunshot? Do they use big powerful guns? Do they use hollow point bullets? What is the condemned's body like? Is it ripped apart? Is there alot of blood? The cause of death would be blood loss, basically. After the bullets penetrate the heart, does blood pressure drop immediately? Is there any chance the condemned feels anything? I've seen videos of Chinese Executions where the condemned receives a bullet to the back of the head. That seems instantaneous. They usually set it up so the body falls right into a grave that the condemned may have dug him/herself. It seems efficient.