I have a tikka in 25/06 and 308 caliber and have shot one hole groups with both at 100yds.Some of my shooting buddies have tikkas and sako's in 7/08,243,22/250,300wsm and 30/06.So I get to shoot a lot of different calibers in the tikka,Have to give credit to the tikkas because I have shot one holers with every one of them except the sako in 300wsm.
One buddie has 2 300wsm tikkas,2 300wsm sako's and one rem in 300wsm He shoots 180 gr sst's in all of them but I have shot some tight groups with the 2 sako's but have yet to shoot a one holer with one.I am sure though if I worked up a load for the sako it would do it also.
Don't think you would go wrong with either the 243 or 25/06 in the tikka.