New poster here and looking for answer to question I posted over on main message board. Would like opinions on ballistic and inherent accuracy differences between these two cartridges. Want to build 6mm bore dual purpose rifle for varmints/casual target use to be built on a repeater bolt action. After research I have learned there are reliability issues with feeding the 6BR through a magazine due to the short fat case design. Can 6mm/.22-250 be a viable alternative to 6BR in equally well built high quality target grade rifles? Realistic maximum range would be around 800 yards. I am striving for efficiency and relatively long barrel life and am not interested in high capacity cartridges such as 6/.284, .243AI, etc. Bullets used would be in the 85-107 grain range through a 28" barrel of appropriate fast twist. Thanks for any info or thouhts, pro or con.