Safety

Post a picture on a gun forum of someone posing with a finger on the trigger and not extended down the frame and you won't hear the end of it.

Pedants come out of the woodwork to point out the safety violation.

It's annoying, but it also means the safety training is working.  More and more know the Four Rules, and a subset of those follow them (wish it was a larger subset...)

L.S./M.F.T  Lucky Strikes / Means Fine Tobacco

Loaded, Stupid
Watch the Muzzle
Finger!  Keep it off the trigger until you mean to shoot
Target, be sure of it and the stuff behind it

or...

• Rule #1: All guns are always loaded. 
• Rule #2: Never point the gun at anything you are not willing to destroy 
• Rule #3: Keep your finger off the trigger until your sights are on target and you have made the decision to shoot. 
•  Rule #4: Be sure of your target and what is beyond it.

But what about other safety rules?  We don't get to use live grenades at the range, so we have no set of rules baked into the gunnie culture's DNA on those.  Or the pedants would be out in force over this cheesecake:

Daddy like!

So, what are the 4 rules for grenades then?  You know, in case there is a boogaloo and all us gunnies are going around with a bandolier of them like Randal 'Tex' Cobb in Raising Arizona?

1. Secure your grenade in an appropriate grendade pouch.  In fact, leave them in the crate as long as you can.
2. OH MY GAWD, BOOT, why haven't you taped down your spoons?  Did you even get signoff on carrying these?
3. Get this Boot some potatoes to carry, he's not ready to go anywhere near the live ones
4. Remember, after you pull out the pin, Mr. Grenade is no longer your friend.