Abstract: A latching system permits a firing head to be lowered into a wellbore and reliably coupled to a perforating gun previously lowered into the wellbore. In a disclosed embodiment thereof, the latching system includes a tubular collar associated with the firing head, and a stinger associated with the perforating gun. As the firing head approaches the previously lowered perforating gun, shearable studs projecting into the interior of the collar are received in external side surface J-slots formed on the stinger. The latching of the collar studs in the stinger J-slots permits the firing head/perforating gun connection to be verified simply by pulling up on and creating increased tension in the structure, such as a slick line, used to lower the firing head to the perforating gun. After the firing head is used to detonate the perforating gun, the spent firing head may be retrieved by pulling it uphole with sufficient force to shear its collar studs.