I am happy with my 284-Win for 600 and 1000 yards, but particularly more so for 1000 yards. For 600 yards I would like to try something different, such as one of the 6mm cartridges. Several of my shooting friends shoot and enjoy great success with some of these; namely, the 6mm BRX, BRDX, Dasher, and TAC40. I understand that the final successful performance will be highly dependent on me, but I would appreciate if you would share your insights on these cartridges; primarily, pros and cons not only in shooting performance, but also in producing these rounds. Thanks! Alex PLEASE NOTE: To avoid confusion and make it easier as to whom I am, I have changed my user name from Nando-AS to Alexander-M. Nando was my nickname as a youngster, and it should be easier to identify me by my proper name, Alexander, now that I am a little older.