The NRA recommended ballistic ball for personal defense is a fluted copper jacketed hollow point ball such as this one:
The concept is the ball in the process of stopping the bad guy will expand so that most if not all of the energy in the ball will be absorbed by the bad guy making it more likely he or she will stop their unlawful act or acts causing the defender to fear for his or her life or the life of another in their presence.
When the ball expands it has a much larger surface area causing the absorption of the energy referred above. I teach and have written in my book OREGON CONCEALED A practical guide for everyone. the mantra Practice, Practice, Practice. These are the 3 Ps of success in defensive shooting. A defensive shooter is in total control until the trigger is pulled and report of the discharge has been heard. Part of the purpose of the practice concept is that once the bullet has left the barrel of the handgun, it knows not who the bad guy is. A defensive person does not want to shoot an innocent in the defense of self or others.
Into this mix the new "Radically Invasive Projectile or R.I.P." has been introduced. It has been reviewed by many companies and independents including usacarry.com
While minions of legislative whores and prostitutes at the federal and state level work to enslave the lawful, to reduce the ability of the lawful to protect themselves and their loved ones, to destroy Liberty and Freedom, industry has stepped up to fill a void as it often will in the American system. They have recognized the need for those of us who actually want home defense in a timely manner. Thus, R.I.P. as another tool to assist the bad guy in understanding he made an invasive mistake entering a home protected by modern technology.