This UPPER ASSEMBLY has the following standard features:
M4 Feed Ramp barrel extension
T-Marked forged upper receiver
1-9" twist, 6 grooves, right hand
5.56mm chamber (shoot either 5.56mm or .223)
11595E (SAE 4150) Barrel steel
F marked Front Sight Base
Manganese Phosphate finish barrel
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 forged A2 front sight base with bayonet lug, not the cheaper cast front sight base which can break. It sports CARBINE handguards (smaller in diameter than M4 handguards which some people find more ergonomic) with ALUMINUM 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 184.108.40.206 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 heavy-weight (.950 diameter under the handguards, .750 under the front sight base) dimension their full length which alleviates barrel whip and enhances accuracy in semi auto fire and helps dissipate heat. 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 FORGED A3 upper receiver with built in Mil-spec M1913 Picatinny accessory rail with the correct rail numbers engraved, made from certified 7075T6.511 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.
PLEASE NOTE: For CHROMED barrel interior 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 chromed barrel. Do NOT just put it in the special instructions. Here is the link: http://blackthorneproducts.com/cart/index.php?main_page=product_info&cPath=0&products_id=300
Since this parts kit does not include the receiver, no FFL is required. Like all of our AR parts kits, this is MADE IN USA!
This product was added to our catalog on Saturday 19 January, 2008.