Capped

A term used for very old firearms. Usually the ones made in or before the 1800s, and for a gun to be "capped" basically refers to the percussion caps that were slipped over the "nipple" of a Muzzleloader firearm, which would ignite the powder inside the Muzzle of the gun once there was a sharp tap that was delivered from the hammer of the gun, as it would drop down and hit the cap, igniting the powder inside the gun, shooting off the black powder ball or bullet stored within the gun.

His wife tried to stop him. But Harold already had his gun capped and loaded ready for the man who he saw kissing her.