A Tikka in 6 ARC probably is the one gun solution.
The 308 is a great cartridge all around- way better than most now think. It’s one of the few options for a cartridge that has enough barrel life to be used as a trainer as well. It can be a one gun choice, but recoil is higher than one really wants for full time use.
The 6.5cm is what people thought the 308 was. But, barrel life is enough lower to be a problem for a true one gun solution, and it still recoils a bit more than optimum.
The 6cm is great, but its barrel life is short enough that it is not really usable as a trainer, and it is more a replacement for a “magnum” for most hunters.
The 223 is the trainer cartridge, everyone should have one, and it is good for hunting to around 450’ish (yes, it can kill well at much longer ranges). However, there are a couple of states that don’t allow it- this only actually matters if you currently hunt in those states- buy guns for what you actually hunt, not what you may hunt.
Enter 6 ARC: near 223 and 308 barrel life- true practice gun capable. Well below 6cm recoil, 600-700 yard terminal range, $20 a box good factory ammo. Easy modification to bolt to work in a Tikka.