Best long-distance 7mm or 30 cal rebarrel for Tikka T3x with .473" boltface?

[BringBackThe80s]

I thought tikka used the same receiver for short and long action just change bolt stop and mag ?

I already swapped the bolt stop and got 30-06 mags so I can load .308 and 6.5CM as long as I want to. But I think 3.35" is the longest COL that will fit in those 30-06-length Tikka mags.