Rifle kit, M4A3, PISTON OPERATED

AR15 / M16 A3 Complete Parts kit LESS lower receiver, with 16" inch M4 contour barrel and A3 Upper receiver. Item # AR-RKM4A3PISTON. This 5.56mm caliber barrel is 16" long, threaded the standard 1/2 x 28 tpi, and has an A2 flash hider with the correct crush washer. The barrel has a machined from bar stock (NO castings) gas block with an M1913 Picatinny rail and a PISTON OPERATED, short stroke gas system. This system features a gas block with ADJUSTABLE gas settings (normal, dirty, and cut off) with a Picatinny rail built in for easy attachment of accessories (Rail is 1.200" above centerline of bore) and a hard chrome plated gas piston made from S7 tool steel. Also included is a ONE PIECE bolt carrier with integral gas piston lug. This system is more reliable, cleaner, and runs cooler than other systems. It sports M4 contour and length handguards with full heat shields, and a correctly sized gas port for reliable function. The barrel is machined from chrome-moly, high vanadium steel and hardened to a U.S. government Mil-spec of Rc 26-32. The barrel, and all external steel parts, are manganese phosphate finished IAW 5.3.1.2 of Mil-STD-171, the U. S. government's recommended protective finish for steel. This finish not only looks great, it affords complete corrosion protection. These barrels are of Mil-spec M4 contour (.750 under the front sight base) complete with the M203 groove in the front. This contour is the perfect balance between light weight, heat dissipation, and accuracy. The barrel is button rifled with 6 grooves, right hand, 1 / 9" twist. The 1/9" twist is best because it handles the widest variety of ammunition and bullet weights. The barrel is mounted on a A3 upper receiver, T marked and made from certified forgings, hardcoat anodized IAW Mil Spec A8625, Type III, Class II, black per No. 37038, Table IX with nickel acetate seal, as per the Mil-spec. The upper features a forward assist and hinged ejection port cover. The buttstock is the heavier wall, stronger (1.160" OD) M4 buttstock (not the cheaper carbine buttstock). This buttstock features 6 positions for maximum shooter comfort, reinforced design for heavy duty use, and the correct M4 lock nut. All semi auto lower receiver parts are INCLUDED as well as semi auto bolt, integral lug carrier, and charging handle. The upper is COMPLETELY ASSEMBLED. Each and every part to the gun is included EXCEPT the stripped lower receiver! (A complete firearm is pictured, the lower receiver and magazine, even though shown in the picture, are NOT included) Add $50 for CHROME LINED barrel and chamber, (You must ACTUALLY Order part # AR-CHROME on your web order form, if you do not see it and it does not charge you $50 on your form, you have not ordered it and will not receive a chrome lined barrel. Do NOT just put it in the special instructions). Since this parts kit does not include the receiver, no FFL is required.