BRAND NEW- U.S. Manufactured BPP11E Nitrided Riffle Barrel. These are the quick change light contour barrels for the HK21E,HK21EK, HK11E, HK11K, BPP21E, BPP21Ek, BPP11, BPP11K system and factory barrels are getting extremely hard to find. A must have spare part for your HK rifle or Machine gun,