I believe the main issue with handloads is that with no factory-spec ammo to test, the forensic boffins will not be able to give a proper estimate of HOW FAR AWAY the shooter was from the shootee when he pulled the trigger. If that question is a key element of the police investigation, handloads will cause you serious problems. Most SD shootings occur at five to seven FEET. If the shooter is a cashier at a liquor store, and the dead guy is lying on the floor six inches from the counter that the register is sitting on, no sane person is going to claim the cashier somehow shot him from 50 feet away.
The goal in a SD shooting is not to have the attacker die at some point, but to INSTANTLY INCAPACITATE the attacker, so he CANNOT continue his attack. Plenty of cops have been killed by BGs who had fatal wounds but were NOT incapacitated for the short time needed to squeeze the trigger and kill the cop. May, 1986 with the FBI in Miami, anyone?
In 1964 in St. Louis, there was an incident that we would now call a carjacking/kidnapping, where a BG with a knife forced a woman parked at a supermarket to drive him around in her car while he rifled her purse and looked for other ways to steal money to buy drugs. The woman tried to alert others to her predicament, but for over an hour no one noticed, including the attendant when she stopped for gas.
Finally, a police officer saw the car being driven erratically, and pulled the car over. The woman jumped out of the car and ran. The officer drew his gun on the guy in the passenger seat, and ordered him out of the car. The man complied, then lunged at the officer, and the officer shot him. The wounded BG grabbed the officer's .38 revolver with both hands and took it away from him. The officer ran to his patrol car to radio for help, and the BG fired two shots at him. The officer radioed for help, then collapsed in the street.
The station sent out a call that said "police officer in need of aid, supposedly shot."
Two officers close by responded to the call. One began to aid the fallen officer and the other chased the wounded BG into the area of the Pruitt Igoe housing project, exchanging shots with said BG.
Then another officer, from the canine unit, arrives at the housing project. He and the cop giving chase decide to circle the building from opposite sides to get the BG. The first cop giving chase hears a shot, and then rounds the corner and comes face to face with the BG. Officer and BG fire at the same time. Officer's bullet hits BG in the chest, BG's shot penetrates cop's left forearm, ricochets off the badge on his chest, and hits his right hand, causing him to drop his gun. The twice-wounded BG staggers off.
Yet another cop sees this exchange of gunfire and fires 6 shots at the BG. TWO MORE cops (one of them a Project policeman) join in the shooting and BG falls down from his wounds and is arrested.
More officers arrive and find the canine officer on the other side of the building, DOA of a gunshot to the head. BG survives.
A BG with a knife gets shot, THEN takes the .38 away from the officer that shot him, and wounds two officers and kills one more with the remaining 5 rounds in the gun.
The dead canine officer leaves a widow and four children, one of them a 12-year-old boy.
The boy grows up and goes to work for the government. He is strongly anti-gun and spoke out often, both in print and on television, against Concealed Carry in Missouri during the twelve years it took us to get it passed. What is his position in the government, you ask?
He's our Prosecuting Attorney.
If he ever prosecutes ME for using ammo that is "too powerful" in a self-defense shooting, my lawyer is going to put him on the stand, make him read aloud the official police report of his father's death, and then ask him what would have happened if the officer who first shot his father's killer had been using a more powerful gun/ammo combo...