[LC Tikka]

Hi
I have sanded the channel after fitting a new barrel, the material removes easy.  If there is a lot of interference rough it out with care.  Once close use emery tape under the barrel, the back of the tape may be abrasive so protect the barrel surface, I used paper towel on the tape.  Work the tape in and up the channel with a sawing action. (you may need to lift the barrel/action parallel with packers to get started) If you want more clearance, double the tape etc.  With this method the result is an even clearance.
LC

[LC Tikka]

Watch using the Std Tikka rings as they are 26mm diameter not 1″.
If you take the small bottom piece and place it onto the scope tube, it will move/wobble also showing a visible clearance at the sides.  Not the right fit to support the scope tube!!
The top piece conforms easily with screw tension.
Do the same on a old 26mm tube and the bottom piece fits perfectly, no movement or clearance.
Why?? I think Tikka want a multi fit mount.

[LC Tikka]

The bolt should never be tight with factory ammo as any SAAMI spec ammo will fit any SAMMI spec chamber.  That is the purpose of the SAAMI regulations.
Have the gunsmith look at the chamber and bolt, if there is any real problem get the Tikka Agent involved.
PS: keep the bolt lugs lubed always as a jammed or tight bolt will score the lugs if dry.

[LC Tikka]

I just don't lap.
I centre the reticle, sit the scope in the rings (not tight) and look at a target (20m) through the scope and bore.
When I see that the scope and bore are not aligned, I lap the bottom halves only with a 25mm bar and emery tape, left or right/down until alignment is gained.
The rings are usually no longer round, so I bed the scope into the bottom pieces aligned to the bore, using Devcon Alu. Ensure the rifle is clamped plumb.  Press the tube well into the devcon, after final alignment is confirmed tape scope in place to stop roll while devcon is curing (top clamp is not needed).  Clean up straight away with a pointed ice cream stick tool, follow the ring edge for a really neat job.
The top ring will still fit (check & bend if needed) as it is flexible and has clearance within the screw holes.
The scope will now have a perfect stress free fit.
Of course use a light coat of release agent and make 2 pine cradles & wedges to pop the scope tube from the devcon with the clamp screws loose.  Clean the tube and ring bottoms free of release agent.  Mount the scope and align the reticle plumb.

This process is also important when using the std Tikka Alu rings as they are 26mm not 1in diameter, the bottom piece will noticeably wobble on a 1in scope tube.