I've pulled 5 or 6 factory tikka barrels. New rifles aren't horrible, but after ones had a ton of rounds through it, heat cycle wise, I feel they get worse. I have a SAC barrel vise and all associated inserts. I had one that was tight enough it required to people. I had the Bugholes inside action wrench with 24" breaker bar, and an 18", box end wrench on the action flats around nose of action loaded with what felt prob 200# of torque, had a buddy hit the action tenon area with a large flat punch to shock the steel and it broke free. When I buy a new Tikka I break the barrel free and re-torque to 100'/# and some copper anti seize, zero problems there forward.
My smith has cut barrels for around 30 different Tikka actions that he was able to measure, and he said headspace varied by about 005 between all them, so he prefers to measure prior to cutting. He's also anal a out his headspace specs. I know other companies that do prefits have a known range of headspace, they chamber to specs in the middle of range, that way you will be right at go, to go plus 004, which is well within Sammi specs. Tikka are prob most consistent mass produced action headspace, but they're not nominal. Hand fitment is still recommend if you want an
exact headspace.