Proof Research 6 ARC AR Type Carbon Fiber Barrel is much lighter, more durable, and accurate than traditional barrels. These barrels will fit into your 6 ARC AR style rifle. Carbon fiber not only reduces barrel weight by 50% or more but also increases the overall durability. Each barrel features the patented Caliber Matched Gas System (CAMGAS) which gives you a gas system that is tuned specifically for the cartridge and length of the barrel. The result is a recoil impulse that is noticeably softer, less fouling in the receiver, increased reliability of extraction, and less wear and tear on brass. This helps keep you on target and shooting while taking advantage of the latest high performance cartridges.