Abstract: In the representative embodiments of the new and improved methods and apparatus disclosed herein for controlling multicharge perforating guns or core-sampling guns, the gun-control system of the present invention includes a selectively-operable multi-contact switch assembly operative from the surface to sequentially connect a group of electrically-detonatable charges into a firing circuit for consecutively firing the charges on the gun. An array of serially-connected Zener diodes cooperatively associated with the switch assembly provides indications at the surface showing which of the several charges is then connected into the gun-firing circuit. The new and improved gun-control system also includes a shot-monitoring system which provides additional surface indications from which it can be determined whether the charges on the gun are being successfully fired and, at least approximately, that they are being consecutively fired.