I found an issue today when putting together another Tikka 22 Creedmoor I just got back from the smith.
Using a high desert bottom metal (I’ve used over a dozen on Tikkas and none have had this particular issue so far) I was getting a fire on close of the bolt once torqued down. Even on very light action screw torque values (30” lbs).
After pulling my hair out for a couple hours I noticed the rectangle cut out for the trigger itself was VERY close to the trigger. It was, in fact, after getting good light and camera on it, touching the trigger ever so slightly and causing the gun to fire on bolt close.
I filed the rectangle trigger cut out until I had a significant enough gap in between the trigger and cut out. Issue is 100% resolved.
If you use an aftermarket bottom metal, ensure of two things…
1: The trigger isn’t touching the trigger guard anywhere, ensure minimum 1/16” of clearance on all sides.
2: The action screws aren’t slightly protruding when fully torqued down. You’ll need a good light to check the front. Pull the bolt and easily check the rear. File them down as needed.
Another reason that the factory plastic is the most reliable solution for these guns.