I was not in the military so someone that was will have to answer this:

When do the soldiers have a round in the chamber?

Always one in the chamber, The evil people have one in there's.

Originally Posted by Cat

Always one in the chamber, The evil people have one in there's.

I did some Google research after I posed the question. And the answer I found was "it varies". The most concise answer I found was this:

"That's a decision made by the commander based on the operation's rules of engagement (ROE), the mission and risk factors."

So the commander decides whether the risk (to the soldiers) is greater with everyone walking around with a chambered round and ready for a fire fight, or is it safer for the guys to be near-ready with an empty chamber.

Good point about the military. In combat chambered with safety on. Outside of combat even in armed security roles loaded mag in and empty chamber was my experience. Commanders discretion makes sense as well. We had 1911's and got pretty good at sling shotting the slide at speed. Dumb tactic though. Never been a fan of training to the lowest common denominator.

Chambered is the way to go and is safe providing the holster is appropriate to the model and the handler doesn't become complacent and make an error. The most dangerous time with a striker fired weapon and no manual safety like a Glock isn't carrying or even drawing but rather reholstering. Finger off the bang switch and slow and deliberate with each and every reholster. Try appendix IWB carry around the house with an empty chamber and you'll get the point.