Sunday, December 2, 2012


Army and Weapons | AR-15 | The AR-15 is a modular weapon system, primarily manufactured by Colt and several other companies. It is the basis for the M16 series of service rifles currently in use by the U.S. military, the C7 and C8 series of service rifles currently in use by the Canadian military, and for many semi-automatic rifles currently manufactured by several companies.  Most AR-15 models generally utilize the semi-automatic fire control group - the selector switch has options for SAFE and FIRE. These weapons are found with a modified hammer assembly, a modified disconnector, a modified trigger assembly, an unmilled shelf in the lower receiver (sometimes blocked to prevent the installation of a drop-in auto sear.

 particularly on rifles produced during the 1994 Federal Assault Weapons Ban in the U.S.), and they lack an auto sear. On the hammer, there is no notch for the auto sear to catch when the carrier cycles back. The selector switch allows the sear on the trigger assembly to catch the hammer as the bolt carrier cycles rearward, preventing the hammer from re-engaging the firing pin and firing another round until the trigger is pulled again.  To further prevent conversion to full auto, some manufacturers use bolt carriers modified to prevent engagement with an auto sear, if one were to be installed; approximately 1.25 inches of steel is milled off the rear part of the carrier, preventing the auto sear from releasing the hammer to fire again.
Country of origin : United States of America
Designer : Eugene Stoner
Weapon type : Assault rifle
Manufacturers    : Colt, Colt Canada (formerly Diemaco) Fabrique Nationale, Bravo Company Manufacturing, Lewis Machine & Tool, Noveske Manufacturing, Smith & Wesson, Daniel Defense, Armalite, Bushmaster, DPMS (Panther Arms), Stag Arms, Spike's Tactical, Windham Weaponry, Oberland Arms, Astra Arm, various other manufacturers

Rifles manufactured for export or military sales have the automatic fire control group; the selector switch has options for SAFE, SEMI, and BURST (or AUTO). These weapons are found with the M16 hammer assembly, the M16 disconnector, and a trigger assembly that allows for the auto sear to function as intended in conjunction with the auto selector switch. The M16 lower receiver has a section of its shelf milled lower to accommodate the auto sear, and an additional hole (the sear hole) is drilled into the lower receiver to hold the sear in place.