Dick,
TV will be shooting two matches on Saturday of Light Gun and Heavy Gun. 6 minutes for unlimited sighters then 5 record rounds for LG and 10 record rounds for HG. If your gun is sighted in anywhere near the target for that distance, you should not need but 5 to 8 rounds to get on target. Then if you win your relay in either class, tou will repeat the process in the shoot off to determine the match winner. So in LG have at least52 rounds and HG you can take 72 rounds. This will give you enough ammo if you are fortunate enough to win everything you compete in at 1000 yards.
I don't know if they are shooting one or two 600 yard matches on Sunday but in both classes, it is 5 record rounds per target and you will shoot 4 target per class. The only difference is on the 2nd thru 4th targets you only have 2 minutes for sighters, as you are already sighted in for the distance. I would go with needing about 75 rounds per 600 yard match. That is providing that you don't have to shoot over because someone fired on your target by mistake, ( it does happen, as we are not perfect ).
Good luck & have fun, it's only a game
Danny