As the military rep for Lasermax I spent last weekend shooting and testing our 1202 sight on the M-4 with the Marine Anti-Terrorism company. We fired everything from low brass birdshot to buckshot to slugs. No malfunctions at all with the 1202 attached. Used the laser at low lighting conditions to fire slugs point of aim point of impact at 50+ yardsIt was a tackdriver. Balance and handling were fine the Marines said they would like to have them on their M-4s for the next deployment. Any body out there want more info drop me a line.