Abstract: In a grease gun having a handle that is manually manipulated from a position extending along the side of the grease gun body to a position oriented at an angle relative to the body to charge the pump of the grease gun with lubricant or some other liquid contained in the gun, and then is moved from the angled orientation relative to the grease gun body to a discharge position or back to the position where the lever handle extends along the side of the grease gun body to operate the pump to discharge the lubricant or liquid, a lock mechanism locks the lever handle in its discharge position extending along the side of the grease gun body preventing it from being moved to its charge position.