There is a wealth of information on caliber selection here: http://www.snipershide.com/forum/ubbthreads.php?ubb=postlist&Board=8&page=1
Be aware that with any of the "overbore" cartridges such as 300WSM, 7mm WSM, 300 Win Mag, 6.5-.284, etc. that your barrel life will be shortened to ~1500rds...