Re: Tikka Accuracy Problems
Try other ammo.
I know it's not fun to buy 3 or 4 or 5 or 6 types of ammo to see what it shoots well, but that's what you have to do. I have pistols and rifles that shoot some loads very, very well and other loads shoot as poorly as you describe. If you know anyone else with a 270 see if they have a few different loads you can try.
After you've done that, then you can decide what to do next.
Oh, and this is assuming your scope is good. Consider swapping a known, good scope and see if that helps. I've had three (3) go bad in the past year, and two were excellent performers last year. Rifles went from terrific to terrible and in the end it was the scopes. One of the scopes was brand new, too.