The Criterion Barrels Ultralight contour is a replica of the original government/A2 profile. It is a lightweight option for those who require a hard use barrel without any added weight. If you are looking for a handy and versatile rifle configuration, this is an excellent option.Headspace (the bolt to barrel fitment), must be checked for optimal performance and reliability. Proper headspace produces consistent chamber pressures and seating depths which results in increased accuracy and reliability, while reducing wear and tear on internal parts and components. 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 feedingRifle gas system compatible with AR15 gas tube systemGas hole tune...