I have a flattop 20" RRA with a chrome-lined BM 1/9 barrel. The barrel was turned by KKF to A2 profile (light under HG) with KKF's A2 brake permanently attached. I know you've heard it before, but this really shoots SA 55 gr. into about 1" at 100 yards, and BH 68 gr. into 0.7".
I'm looking for an exc. 16" flattop upper, post ban, for a trade. I'd prefer M-4, but would also be interested in a free float 16" or other profile. Bolt, carrier, CH would be included in both directions.