Dude, everyone has different rules. And I didn't make that rule up. There are hundreds of people that follow the same rule. It's a matter of what people are comfortable with. There is no arguing that an empty chamber can not discharge a round. Period. I hear the argument that chambering a round makes too much noise or takes too much time in a hunting environment. Bird hunting, yes, I can see that it isn't feasible. But when it comes to big game hunting with a bolt action rifle, I disagree with the previous argument. My answer to that would be to become a better hunter.
If I can take an extra precaution to keep a bullet hole out of my kid, myself, or my pickup, I'm going to do it. By the way, lots of people drive drunk too. I choose not to.
Empty guns have killed a lot of people over the years. Treat all guns like they're loaded
Jeff Coopers 4 Rules of Firearms Safety:
1.All guns are always loaded.
2.Never let the muzzle cover anything you are not willing to destroy.
3.Keep your finger off the trigger until your sights are on the target.
4.Be sure of your target and what is beyond it.
NRA's 3 Rules of Firearms Safety (written by Jeff Cooper, lol)
1.ALWAYS keep the gun pointed in a safe direction.
2.ALWAYS keep your finger off the trigger until ready to shoot.
3.ALWAYS keep the gun unloaded until ready to use.
If I am hunting I am ready to use it. If I am carrying concealed I am ready to use it. If my gun is for home defense I am ready to use it. Pretty simple really.
And for giggles:
Project Appleseed's 4 Rules of Firearms Safety
1.Always keep the muzzle in a safe direction.
2.Do not load until given the load command.
3.Keep your finger off the trigger until the sights are on the target.
4.Make sure those around you follow the safety rules.
Canadian Firearms Program
Assume every firearm is loaded.
2.Control the muzzle direction at all times.
3.Trigger finger off trigger and out of trigger guard.
4.See that the firearm is unloaded. PROVE it safe
I am an NRA Pistol, Rifle, Shotgun, Personal Protection Inside the Home, Personal Protection Outside the Home instructor as well as other disciplines and I follow and teach Jeff Cooper's 4 Rules. As always, Your Mileage May Vary