Abstract: An attachment system for mounting an accessory device to a longitudinal rail along the frame and forwardly of a trigger guard; said rail configured with at least two longitudinal grooves, one along each side of the rail, and further configured with a transverse slot in the surface of the rail; an accessory including a pair of longitudinal tongues, said tongues complimenting the longitudinal grooves for retaining the accessory device on the rail; a compression spring in a recess area formed in said accessory upwardly biasing a latch, on the accessory device housing and pivoting on a pivot pin; said latch containing a transversely disposed elongated protuberance having a width slightly less than the transverse slot of said rail for being received therein that co-acts with the transverse slot in said rail to prevent further longitudinal movement of the accessory device along the rail.