Lou, you said Temple Ranch? Need more info on that one. Your 30-06 won't be "too much" power for the sheep. It should be quite effective depending on the round you will be using. Then again, it would be good to have more details in order to give you a good answer. What ranch, terraine, etc...? What type of sheep are you going after? I have taken a few with my 7-30 Waters TC. Both with the factory ammo, and handloads. More details please.
markc