hi everyone i recently purchased a 6 mm predator barrel form AR 15 performance . All i can say is WOW using 108 berger's h 4895 27.7 gr i get 2712 FPS SD of 10 and it shoots .370 inch groups all darn day even after 30 + shots . at 825 yard it shot a 4.5 inch group at least 7 out of the ten shots fired it was windy 18 to 23 mile an hour gusty !!! 3 were out at 3 O' clock by 5 inches . now you kno that barrel rocks !!!