The present invention is a projectile launching system having an independently operable gas powered less-lethal launcher, which is capable of firing projectiles containing either incapacitating, debilitating, or marking agents for use during those situations when lethal force would be an inappropriate response. The gas powered launcher is ergonomically designed and comprises a receiver housing and receiver that are detachable from a stand-alone stock so that it can be attached to a mounting bracket located underneath the barrel of a rifle and, therefore, integrated with such rifle in order to provide both a lethal and a less-lethal capability for the user. One of the ergonomic features of the receiver is that it is designed to releasably carry a compressed gas container in a way that presents a favorable profile and a convenient and efficient trigger location, even after attachment of the receiver to the barrel of a rifle.