Ruger AR pistol has a barrel size of 10.5 inches with a 1 in 8-inch barrel spin.The barrel is shrouded by a free-float hand guard that just touches the rest of the rifle at the barrel nut, guaranteeing that stress on the hand guard will certainly not affect objective of the gun.The hand guard is machined with M-LOK slots for the add-on of aiming lasers, flashlights, as well as various other Ruger AR 556 Accessories.The AR-15 rifle was established by Eugene Stoner as a possible armed forces weapon.The Ruger AR-556 pistol is one instance of an AR pistol decriminalized by this declaration.The AR-556 has a barrel length of just 10.5 inches and also an overall size of 25.3 to 27.9 inches.