If I had a dollar every time an AR or AK bolt was closed when people started downrange, I could buy a couple pounds of powder. This unsafe act is RAMPANT at one of the clubs where I belong. I could buy another pound of powder when I questioned them on it and when they pulled the bolt back, a loaded round ejected. A rifle without a magazine is not an unloaded rifle. Ironic and for whatever reason, LEOs and combat vets are the worst offenders.
Which is why we provide. and require the use of, chamber flags on all firearms when range is called cold.