I've been shooting Tikkas for over 25 years, starting with the 695 in 7mag. To date I own/have owned 7 of them including the T3, T3X, and CTR. I've never replaced any stock parts with the exception of a Limbsaver pad which I love. I've also never taken out the factory 'nubs" to fully free float as it's never been necessary, and I run the factory springs as low as I can get them which is about 2lbs. No issues, ever, getting sub MOA hunting rounds. Rings include Opti-loc, SM, Warne, and even the factory rings given away with the T3, but then again I don't use a cheater bar to torque rings/mounts.
FWIW, the OP should start from the start and go back to original parts and go from there. If that were a Leupold on top there would have been a slew of "your scope sucks" as the culprit by now instead of blaming it on a lug issue.