Years of experience producing barrels for the United States military has lead to some of the longest-lived, most accurate rifle barrels available for the AR-15. FN, producer of the world's most battle-proven firearms cold hammer forges high-strength 41V50 chrome moly vanadium barrel blanks to produce rifling and contour in the same go for exceptional repeatability and incredible durability. Each barrel is individually magnetic particle inspected to be free of flaws before having the bore and chrome lined to the same standard as military rifles.