If maximum mobility and extreme weight savings is your goal, the pencil contour is the lightest weight offering from Criterion Barrels. 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. Chrome-lining process is the most refined in the industry and will not degrade accuracy.Honed 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 feedingGas hole tuned for proper function with and without suppressorGas Block dimpled for ease of installation and solid lock-upPrecision-machined barrel extension with M4 feed ramps