Tikka T3 caliber question

[Tarfur]

Hello

I am thinking of adding a Tikka T3 varmint stainless to my collection and could use some caliber info. I´m going to use it for everything from varmints up to caribou and I have 3 calibers in mind. I would like to be able to shoot up to 500 yards on calm days when shooting varmints.

25-06 Rem. I like the idea of something flat shooting and hard hitting but is the 23 ¾” Tikka barrel long enough for this caliber? And what about accuracy?

7mm-08 Rem. I know it´s accurate and that’s about it.

6,5x55 My father has one like this and it seems to do the job but for varmint shooting????

Any info would be good

Greetings from Iceland, Tarfur