[trhway]

Absolutely. It is so fundamental, at the instinct level almost, that it didn't even came to my mind to mention it. Until absolutely necessary, you never chamber your weapon - "what if the trigger gets accidentally pulled!" :)

Even military guards on duty are by the military regulations explicitly prohibited from chambering their weapon until necessary:

209. Часовому запрещается: ..., досылать без необходимости патрон в патронник, ...

and only when the guarded security perimeter is about to be breached and the guard has already issued 2 verbal warnings, only then the guard chambers the round and makes the first warning shot toward the sky:

211. ... Если нарушитель после предупреждения "Стой, стрелять буду" продолжает движение, часовой досылает патрон в патронник и производит предупредительный выстрел вверх.