@zebratron2084 Laser rifles never ejected casings or needed ammo refills or recharging. I could see an argument for retconning/reusing the M16 hardware, build high-densisty chemical batteries into the magazines or clips and turn the entire bolt assembly into a single resonator gas laser assembly (CO2, trace elements argon for good side, neon for bad side for the glow effects), but just hang a lampshade on it or something!