It is complicated, I have done a lot of research on this, you really need to if you consider this method- in the u.s. the rate is 80%, according to government statistics, anyway. To ctb by this method one way is to hit the brain stem, and the brain stem is small, and often people miss it to one side or the other and it goes out their neck and they are not really damaged at all or it can hit the spine and they can be paralyzed. If you don't try to get the brain stem then both mehispheres of the brain need to be badly damaged in order to work- the human brain is designed so that if one hemiphere is damaged, say the left side, the right side can take over for a lot of what was damaged over time, though a person may still be disabled and/or disfigured after this. The human body and brain are designed for survival. Keep in mind that thyis 80% includes many people with a lot of knowledge and experience with guns- for people who don't have this the percent is likely a lot lower. The recoil, or kick, of the gun from the explosion when the gun is fired changes the angle of the gun, sometimes a lot- there are so many variables, and if you survive the results are often very bad- there are interviews with gunshot attempt survivors on youtube- and those are the ones who can still talk, others are too damaged for this. For me this method has too much risk and is best left to people who have a ot of experience with guns or who do a lot of reseach to improve their chances, I still think for me the downside risk is way too much.