I am waiting on several of these barrels to be delivered to me for builds that I am working on. In the mean time, there is a barrel of the same type lent to me by a friend who bought several from AOA to finish his kits. These barrels are well made & correctly chrome lined as far as I can determine. The profile is spot on for populating the RSB, the lower hand grip locking piece, the Gas Block & the FSB. The lower hand guard locking piece milling & groove is the only cuts made to the barrel except for the extractor relief cuts. The barrels are spot on for my builds since the originals are removed or destroyed before shipment to me. Nice to see US barrels done well now!