For comp, you always want the smallest case and the lightest bullet that will do the job. Recoil is not good for your score and increased barrel heat will cause barrels to warp and loose accuracy.
If just paper punching, consider the 6mm and 6.5 if rifle weight is around 10/12 lbs. No use getting beat up. If going all the way to a 22lbs F class rifle, then 7mm is a viable option.
I shoot a 7RM Kreiger barreled Savage using moderate loads. Wonderfully accurate but I use a muzzle brake and a heavy rifle. Not competing so don't care about the final specs. Recoil is very mild. However, barrel does get hot after 10rds.
If you want to be competitive, you should consider a better barrel then factory. The wind is bad enough without having to wonder if that miss was you or rifle.
Jerry