The only time a firearm is loaded and charged is when the player is shooting. No firearm can be loaded until every player is in place on the firing line and the command to make your firearm ready is given.
When the firearm is made ready the player can not handle the firearm until it is their turn to shoot. When the player finishes shooting their lane or changes lanes: the firearm is unloaded, flagged (a small bright plastic piece that shows the firearm is unloaded), and placed on the deck pointing downrange in their lane, or pointed up while changing lanes.