Rather than use real guns with bullets, which is both dangerous and costly, military and police personnel often use modified weapons during their training operations. These modified assault rifles, which shoot bursts of laser light, give them the target practice they need. To give the shooter the real kickback of firing a gun, one firearm simulator manufacturer turned to Humphrey Products Co., Kalamazoo, Mich., to install air cylinders that give the user the recoil feeling.
In this case, the manufacturer needed a system that could sit in the hollow body of an M-16 rifle. Humphrey designed an assembly that consisted of a valve, manifold, and cylinder. The rifle was fitted with a 310 series solenoid valve to provide optimal flow, low current draw, and reliability. A small, modified cylinder (1.5 oz) with a 1/4-in. rod diameter allows the device to stroke up to 4 in.
As the trigger is squeezed, the cylinder rod slams backward, hitting a stop in the rifle butt. This produces a realistic amount of recoil, giving the trainee the feel of actually firing an M-16. After each shot, an internal spring recoil returns the cylinder back to its initial position.
The air supply to the gun comes from a reservoir tank contained in a backpack that connects to the rifle by hose. A battery within the rifle supplies the necessary current to activate the valve.