I only ask because you mentioned one hole groups and while the groups you have posted are pretty good, it is worth remembering that you can turn a Chevy Cruse into a Mclaren P1. DPMS barrels can be shooters, that is for sure, especially for production barrels, but doing a lot of lathing, cutting, threading, tuning, etc may make your .3 inch group in that production barrel worse rather than better. 3 shot groups tells a tale, 5 shot groups tells a story, 10 shot groups tells the truth.