could any one shooting this round let me know how it performs at 300 /1000 yds ,the rig i am building has a 28" bbl 1/8 twist and will start off with 142 smk any info will be very handy thanks . ROD

Rod, welcome to AR! I haven't shot f-class with a 6.5-06 Improved, but I do shoot a .256 Newton, the original 6.5-06 cartridge. Also I have a friend that shot a 6.5-06 AI for years at deer and now shoots a 6.5-284 in F-class competition, and from what I can gather, it should serve you well. Good luck and let us know how it works for you.