Originally Posted by MNBud
I have NEVER had a gun re-load itself, When I drop a magazine and pull the slide back and look into the chamber of any of my firearms and they are empty, they seem to stay that way. You may jack a slide five or ten times and if you have a broken extractor, it in theory could leave a round in the chamber, but if you visually inspect the chamber and it is EMPTY it is going to STAY empty. This gun will be unloaded.
Checking more than once is about us being human and having the ability to make mistakes.
Checking a gun multiple times, and both visually as well as physically, is common practice and is highly recommended...ESPECIALLY when you are about to engage in an activity specifically designed to see if the gun will fire.
I just find some rather peculiar about emphasizing the suggestion to check "ONCE".