I would prioritize shootability, glass, and bullets, in that order. Your Tikka 7RM isn’t the rifle to learn LR shooting with, IMO. That RPR in 6.5 CM with your SS 10x on top, shooting the 147 ELD, would be a great tool. If sticking with your .308, the 155 Scenar would be a good choice, and your Credo 4-16x should work okay.