Probably Time for a Scenario Discussion Re: Use Of Lethal Force
The Fish case was complicated. There were big dogs running loose adding to the threatening posture of the aggressor, and even a screwdriver on the aggressor's person, but the evidence pointed to him not being an immediate threat, not having touched or struck Fish, and the "reasonable man" test failed. Any time you use lethal force that evaluation will be part of the DA decision to charge or not. What would a "reasonable man" have felt, or done, in the same circumstance? Unfortunately, that evaluation is aided by hindsight (which you don't have the benefit of as the situation is evolving around you) and flavored by the personal beliefs and prejudices of the evaluator and ultimately the jury, if it goes that far.
That said, you definitely could be steered by determining what ammo the cops use. Or a check of your statutes. I recommend both and if you still don't get it, you could consult your attorney. Preferably one schooled in, and favorable to, matters concerning firearms and self-defense.
And never stop your own education on matters concerning use of lethal force. Would really suck to be placed in a life/death situation, shoot and survive, only to be charged, convicted, lose your wife, family and freedom. Like Mr. Fish. Did he make a bad decision to shoot? Did the guy in the parking lot? Bet they didn't think so at the time, but i bet they do now...