If maximum mobility and extreme weight savings is your goal, the pencil contour is our lightest weight offering. These barrels feature the most refined chrome lining in the industry to maximize accuracy and durability.FEATURESChrome-lined internally for superior barrel life and corrosion resistance. Our chrome-lining process is the most refined in the industry and will not degrade accuracy..223 Wylde chamber that is designed to safely and effectively fire both .223 Remington and 5.56 NATO ammunitionHoned and hand-lapped rifling for bore uniformity and a pristine internal finish - aids in barrel cleaning and paramount for accuracyFinely polished chambers for reliable extraction and feedingMid-length gas system compatible with AR15 gas tube systemGas hole tuned for proper function with and without suppressor0.625" Gas Block, dimpled for ease of installation and solid lock-up1/2A-28 TPI muzzle threads compatible with a wide range of muzzle devices and suppressorsPrecision-machined barrel extension with M4 feed ramps