The following information on the inspection of police revolvers comes from Section 40 of Shooting by J. Henry FitzGerald. Shooting is also available to purchase in print.
It is very important that a police officer should know how to care for his revolver. First, unload the revolver, look once to see that the revolver is unloaded and then look again to see that you did not make a mistake. Do this first and look again; be sure. See that it is clean and that the side-plate screws and all other screws are tight; otherwise the revolver will not function properly. See that firing pin is not broken; this very rarely happens, but it doesn’t take long to look. Swing cylinder out and pull the trigger; hold up to the light and see that the firing pin comes through the recoil plate; see that the barrel is clean and no obstruction in it. Rub the finger across the firing-pin hole in the recoil plate and see that no burr has been thrown up by the firing-pin coming through the recoil plate, as this will sometimes cause a jam and the condition may be easily corrected with a small, fine file. It is a condition which only exists after an arm has been fired or snapped many times and cannot always be detected at the factory.
Always try the bullets to see that they are not loose in the shells, for if this should be the case the loose bullets will jump forward as a shot is fired, extending beyond the end of the cylinder and catching on the end of the barrel causing a jam. See that no lint, paper, or other substances have fallen between the hammer and frame to stop the firing pin from striking the primer.
Snap the arm a few times to see that all springs and parts are working properly. This would be a fine time for some dry shooting. Stand before the mirror, hands at the side, revolver in its accustomed place; draw five times and snap at the man in the glass; if time permits aim and snap ten times at some small object on the wall. Load the revolver and you are ready for any emergency.