MikeyHad - Since the action has been removed from the stock remove it again and when reinstalling make sure that the action is engaged onto the recoil lug.
I have a friend who has a T-3 that he took apart and when he put it back together it shot about like yours. I took it apart and found that the action was sitting on top of the lug rather than being engaged onto it, reinstalled the action properly and it went right back to grouping like Tikka's genrally do. The funny thing is that with the action sitting on top of the lug it was not that noticable that it was installed improperly.
Just something to check since it has been apart.
drover
