Nd:YAG lasers have been successfully used to demonstrate laser ignition of howitzer propellant charges including bag, stick, and the Modular Artillery Charge System (MACS). Breech Mount Laser Ignition Systems (BMLIS) have been designed, installed and tested on many artillery systems, including the US Army's M109A6 Paladin, M198, M777 Light Weight, Crusader, and Non-Line-of-Sight Cannon (NLOS-C). The NLOS-C incorporates advanced weapon technologies, to include a BMLIS. United Defense's Armament Systems Division has recently designed and built a NLOS-C System Demonstrator that uses a BMLIS that incorporates Kigre's patented square pulse technology. NLOS-C is one of the weapon systems being developed for use with the US Army's "systems of systems" Future Combat System (FCS), Manned Ground Vehicles (MGV) program, and is currently undergoing development testing at Yuma Proving Grounds. In this paper we discuss many technical aspects of an artillery laser ignition system and present BMLIS test data obtained from actual gun firings conducted with a number of different US Army howitzer platforms.