Tikka t3 are normally 1/18 thread unless it's been rethreaded, you can always call up GMK give them your rifles serial number and they will tell you it's thread.
Hi, can I ask you what make are the rings and bases you have in the pics please as I have a set of these on my Remington but have no makers name or numbers on them and I'm wanting to purchase another set. Thanks, Mr Roberts.