CSC carries MCarbo trigger springs for Tikkas.
I don't see CoreTac on the CGN dealer list, so I'm guessing that they're not a sponsor, but they have a Tikka performance center on their site. Barrels, DBM, bolt stops, lugs, trigger springs, bolt handles/knobs, and a bunch of other stuff. They're the only two shops I've dealt with for Tikka parts, but hopefully more will chime in.
