Onboard the ship, all duty weapons were carried were carried with the pre-loaded mags in pouches.
I was one of the few that violated that rule - but only in one circumstance. Whenever I had to go to the bank to pick up payroll money, I would draw a weapon (1911) from the small-arms locker. As soon as I got in the vehicle, I popped a mag in but never chambered a round. When I got back to the pier and before leaving the vehicle, I would drop the mag and place it back in its pouch.
One disbursing officer was robbed and murdered while I was in Jax - but it was done by an idiot sailor on the ship. A couple of years before, one was robbed in Naples and they shot him in the leg. I figured that I had a better chance of surviving a robbery attempt if I started out with the mag in even if I had to rack the slide manually.