I have purchased two barrels in the past couple months. Colt carbine barrel and a Ballistics Advantage 13.7 5.56 barrel. Both failed headspace check. The companies were both, not interested in hearing that information as they just ran checks with Field gages. I am using a Fail Zero BCG. We checked both with multiple bolts from different manufacturers. All hit no go on SAAMI spec gauges. I work at Phoenix Weaponry in Berthoud doing coatings for them. I had the guys look it over for me. They are seeing an awful lot of this in the industry these days. Just don?t understand how the companies can produce products with such unsafe QC. Anyone else running into these issues with barrels ?