I have to strongly disagree with the first statement. I know too many people who have carried the day using their sights and the threat was immediate.
Suggesting that range alone will dictate whether a shooting is justifiable is also interesting. Where do you draw the line? What if the miscreant is at 43, 57, 62 or 78 yards? If you investigate shootings then you should know there are too many variables involved to justify your statement.
As far as leaving if the other guy has a rifle and you are outgunned. Sound advice, but may not be an option for some unknown reason. I may be "outgunned" but that does not mean I have to be "outfought" and I don't plan on giving up without a fight regardless of the distance.
As for the zero. I zero at 25 yards and shoot out to 100 so I know where to hold.
I have investigated more cases than I want to remember. As recently as this morning, I got a shooting case from last night. Over the 38 yrs since college, I have worked about 40 officer involved shootings. To my memory, not one had time to get proper sighting. Yes, there were times when an officer approached with proper sighting and those are plentiful but then most people will not do anything stupid when a uniformed officer is looking down the sights of a gun aimed at you.
Each case is different. The law is fairly explicit in what is justifiable. Those that are not get tried. Those that are get a free pass (although not always free) and those in between are presented to a grand jury. It is difficult to be threatened from 50 feet away unless the person already has a gun on you and in that case, best not try drawing yours. A person can shoot a lot faster than a person can draw. Regardless, distance and threat level will be heavily considered in deciding guilt. I worked a case 3-4 yrs ago where a bar fight had occurred. One guy got himself whipped and threatened retaliation. As the winner got to his car, the loser called him
back out. The winner thought the guy was going to shoot him so a gun came from under the seat and he shot the guy. Yes, the guy had a weapon but it was not produced and was found in his back pocket (Titan 25acp). But at over 40 feet, the shooter could not see a weapon but surmized there was one and immediately fired. He got 12 years and will do four along with a lifetime felony record. Distance is often in the equation. I keep telling young officers and new shooters that life is not as cut & dry in the law as some appear to think. I also know some on Death Row at Angola State Prison that wishes they had not made some wrong assumptions in the law. My statement stands. The greater the distance, the lesser the threat. Just as LEO cannot shoot someone without being justified, a person cannot shoot when on the street because they feel threatened at 100 yards. The only case I have ever had anywhere near that was when a farmer shot a man that broken into his barn and took a couple items. The farmer thought the man to be armed and shot him with a 30-30 as the man headed out to the road and a waiting car. Farmer went to jail.
I see nothing wrong with your zero range. But as stated, change ammo and zero will change. The main thing is being able to hit what you shoot at when it is required. However, the longer the shot, the more closely the shooter will be examined. FWIW: There are a lot of LEO in jails over shootings they thought were righteous.
The above said, anyone is free to do as they think best based on the facts known at the time. But in the light of day with cooler heads and less stress, situations often look much different There are some investigators that lightly run over the case and let it go. I am more thorough and if there are any questions, I will work til the answers are there. So far in my criminal cases, I am 100% successful in court. In my civil cases, I am about 96% successful. I take the law and my work seriously. I would go against my daughter if she stepped outside the boundry of the law and it would hurt me but it is principles I was raised with. I do not turn my back due to kinship, friendship or LEO. Most good investigators are the same way. All we have to offer is our education, training and good reputation. If that gets tainted, we are no longer respected or within the law.