In an exemplary electromagnetic launcher, a housing with breech and muzzle is slidably supported in a carriage supported on a trunnion. First and second electrical contacts are mounted in the carriage toward an axis of the trunnion. The first and second contacts are electrically connectable to receive electrical power from an electrical power supply. First and second augmentation conductors are disposed aft of the trunnion and are electrically connected to the first and second electrical contacts. First and second main conductors extend from the breech toward the muzzle. A current cross-over connection is disposed toward the breech and electrically connects the first and second augmentation conductors with the first and second main conductors, respectively. The first and second electrical contacts and the first and second augmentation conductors may be engaged in slidable electrical contact over a portion of the first and second augmentation conductors, thereby accommodating recoil motion.