I don't have time to dig up all the links, but gun-safety rules -- how many of 'em and what they otta say -- is a hot topic, again.
Here's the thing: those rules -- whatever set you like -- are just a tool. What's the tool supposed to do? They're supposed to keep you from perforating things that hadn't otta be perfed -- walls, floors, friends, family, that guy over there and his dog. And they're supposed to keep you from scaring those around you, too.
Take Cooper's Rule One: "All guns are loaded all the time." LOLwhut? I know some of mine aren't, a lot of the time.... But I do not know about yours; so if you'll please bear in mind that as far as I know, I am looking up the very nostril of Death Incarnate when you sweep me with the muzzle of that unloaded gun, and therefore refrain from so doing unto me, we'll get along fine; I neither know nor care if it's Jeff Cooper or Emily Post who makes you mindful of why it's considered rude.
Do your rules encourage mindfulness? Do they keep you and those around you safe? Then good on yer. If not, well, me and ROs, we've got some questions. Kind of questions. Like, "Would you like to leave now?"
Don't be that guy. Be the safe guy. I don't care what creed you use to accomplish it.
Update: I was not sufficiently clear. My message to shooters is not the cheap and easy, "Be safe!" It's something a lot more harsh: Conduct yourself in such wise that those around you will judge you a safe shooter. And you don't get to quibble. Giving J. Random Guy a peek up the muzzle, breaking 180 on the line, standing way off the firing line and muzzling your wheelchair-bound girlfriend in the back of the head while stuffing a fresh mag in your Makarov and dropping the slide: these are all behaviors I have seen and either spoken up about or departed in haste because of.
The Internet is just some people talking. In the ultimate analysis, anything shared therein about technique or philosophy is just so much hot air that you paid pennies to read. It's what you go out there and do in the physical world that counts. Pick any blamed set of rules you like -- make them up -- tell yourself whatever you need to; but understand that if you are not safe, I will call you on it. Tam will call you on it. Or we will leave, rapidly. A good RO -- and they're not omniscient or all-powerful, so they are gonna miss stuff -- will call you on it.
Tam put it best: Assume you're an idiot. You don't get to decide if you are the safe guy or the horrible example; your behavior will tell those around you which you are. Not your words. Not your cuddly-wuddly wuvability or your big strong silent machismo. You can't chop-logic your way out of crappy weapon-handling, you can't get big, teary anime eyes and be excused, there's no staring it down, you can't appeal to Saint Cooper or the graybeards at the NRA: if you go to the range and do unsafe stuff, you are the guy not to be like. No matter your creed or how many classes you have taken, you don't get a badge or a ribbon or a diploma that allows you to endanger persons or property. You don't ever, ever get a pass on safe behavior; every time you go shoot around people (or in range of ruining their day), you are in the scales of judgment. You were an idiot yesterday and got sent home? You don't have to be one today. Conversely, yesterday's Miss Safety may trip over a brain fade and screw up. See ya! Do better next time!
When you mess up with firearms, people can die. This is not student council elections.
(And another thing -- I'm a faithful member of the Four Rules Church, myself; they're so close to the gun safety my Dad taught me at the ago of 12 it's amazing, considering he was a hunter who never owned more than the same .22 and shotgun all his life and never heard of Col. Cooper, as far as I know. It's comforting to me to hear his, "Always assume it's loaded. Always check to make sure. Don't point it at anything but the ground or a target. You don't touch the trigger until you are lined up and ready. Think about what's behind what you are aiming at, think about where the bullet will go and be sure you understand it," echoed more succinctly. Dad taught me those things in his on-edge, exasperated, you-must-learn-this way, rules he worked out for himself or was taught by his father, brothers and friends and I know they worked. And he taught them not by rote, but first Socratically, as leading questions, and then by example, with the rifle in my hands and his hands hovering ready to make sure I didn't break the rules. Yeah, I use Col. Cooper's rules to guide my shooting and to judge yours. I grew up with them; I know they are a tool and I know that tool does the job).