Guess no one has both a 308 and the 06 chambered tikka T3 .
I have wondered too if this could be done . I too would like to load the bullet closer to the lands .
Then if there was all that space for the cartridge to move back and forth under reciol , would not the nose of the bullet take a beating , or worse the bullet being forced into the case with the reciol.
Darn good thing the rilfes shoot well with the free bore .
Have you tried loading just one round to the rifling ?