All good load advice.
How is the trigger, lbs., crisp? Also, a 7.5 power scope with a regular duplex (I assume) is not going to allow you to aim at a really small spot on the target.
Go to accurateshooter and print off some of their targets to use at 100 yds.
Are you shooting from a solid bench, what kind of front rest and rear bag are you using?
A lot of factors go into shooting the best possible group for each individual gun.