While there are many different sets of "rules" of gun safety, some of them quite long, there is a general consensus among prominent firearms instructors that the following list of the cardinal four rules is primary. This list is endorsed by such prominent gun experts as Jeff Cooper (who originated these rules), Masaad Ayoob, Clint Smith, Chuck Taylor, and Ignatius Piazza.
- Treat all guns as if they are loaded.
- Never let the muzzle of a gun point at anything you do not want to destroy.
- Keep your finger off the trigger until you are ready to fire.
- Be absolutely sure of your target and what is around and beyond your target.
Rule #1 is often modified to a more extreme version, to hammer home the essential point: "All guns are always loaded." Gun enthusiasts generally act this way at all times. People who are inexperienced with guns sometimes violate this rule, thinking that since the gun is unloaded it is safe to "play" with it. That's not even true if the gun is really unloaded, and because human error is often the foremost factor in gun accidents, it is safer to make the extreme assumption.
One potentially fatal assumption is that when the cartridge magazine is pulled out, the gun is unloaded. But there can be one bullet already loaded in the firing chamber.
Rule #2 applies to both loaded and unloaded weapons. Remember rule #1. Even when your gun is unloaded, and you know it is unloaded, you should carry it in such a fashion that the gun still doesn't point at anything you aren't willing to destroy.
Rule #3 is violated frequently by police and criminals in movies and television programs. But properly trained users will only place their finger on the trigger when it is time to fire. The time that it takes to slip the finger to the trigger is miniscule, as compared to the high degree of safety obtained by following this rule. Modern guns never simply "go off". It takes a finger on the trigger.
Rule #4 is self-explanatory. You must know not only what you are shooting at, but what is beyond it and near it. In some emergency situations (a hostage crisis) it might be necessary to take a risky shot -- but you must know what you are doing first, to be safe.
Additionally, there are four rules of gun safety which can be taught to all children who are too young to learn to properly handle a weapon.
Stop! Don't Touch. Leave the area. Tell an adult.
Guns kept in the home for whatever reason should be made safe from any possibility of use by untrained children. This can be accomplished most effectively through the use of a locking device. The role of the gun in the home safety strategy need not be compromised, with the existence of many effective fast-unlocking storage cabinets which can be kept at the bedside.
Guns which are not in use at all, i.e. not in use for home defense, can be stored even more securely unloaded and in a safe with a trigger locking device.