I own this exact rifle and have tested 17 different bullets and powder combinations, with bullet weights between 50 and 100 grains.
First, the amazing think about the Tikka 243 is there's nothing that it shoots poorly. I haven't found a bullet/powder combination that's "worse" than just slightly less than 1.5 (about 1.43 to be very exact) for a five shot group. That is astonishing accuracy across a 50 grain weight difference.
So in the 90 grain class, I load the purple tip Noslers on top of Varget and this is .73 for a five shot real group. Wow. Considering I can get almost exactly the same performance from a 50 grain bullet as well, it sets the 243 up to be an incredibly versatile rifle.
My father borrowed the rifle a few years ago and used a single shot to stack up a buck in his tracks with a 100 grain Hornady. He did not anticipate that kind of killing power from a "little" 243, the deer did not take even one step,it simply crumpled to the ground.
I think the 243 is under-appreciated in terms of versatility as there are many people who own 2-3 rifles to cover the ground that the 243 can easily cover with handloads.
Grouse