Like a lot of things related to firearms, you need the exact rail designed for a Tikka T3, the NEAR based are available from Near Mrg. (just Google it) they run just under $200, usually Richard as a 20 MOA base in stock.
There is not a lot of aftermarket support for the Tikka's right now, so we have to make due with what we can. The NEAR bases are absolutely amazing, great design, great finish and great workmanship. I spent a great deal of time looking for Tikka's aftermarket parts, there just is not a lot out there unlike for the Rem 700. I did find Roedale Persision (Just Google it also) who make a few items like muzzle brakes (for the varmint heavy barrels Tikka's) trigger groups, and a ACIS stock frame.
/cl
