Mike,

An examinaion of shooting scores will indicate to you that the shorter cases are more often the winner in HBR matches. Of course there are more of them in use but they are winners and record holders.   I began with the full size case on the advice of Keith Francis (JGS reamers).  This was many years ago when the 308 Winchester was the common choice, the 168gr Sierra was king, 4895 was about the only powder  used and the 12 twist was SLOW.  Keith told me that he saw lighter and lighter bullets in the future so a short lead was going to be needed.  The .085 of the Obermeyer filled the bill.  He indicated I should get the slowest twist I could (14 at the time), let him build me a reamer and then practice shooting.  He indicated that one of the more difficult challenges of the game was cutting and forming brass in a uniform manner and since I was a beginner if all I had to do was cut the necks I could concentrate on shooting.  I followed his advise and it worked.  The shorter 30's have come in to their own, there are more and better tools for forming brass, there are more barrel options and powder options than you can shake a stick at.  I am not sure where you are Mike but I suggest you consider whichever case size is more used in your area as you can get more help from other shooters.  If you are isolated I suggest the full 308 as you only have to cut necks and go shooting.  That will get you started easily, let you practice and as you go to matches you can make your choice from all the options you will see there.  I would be happy to send you blueprints of the Obermeyer, the 30 Cribbs (modified IMHSA that holds the 300 yard world record) the 30X1.8 (100yard record) and another short 30 (one of Stan Johnsons) for you to look at.  Like Randy and I always say, "If you can not beat them, confuse them".

Larry Cribbs