Mine shoots clover leafs all day long at 100 yards. I use Winchester BST. I don't know if it's true,but I have had 2 different gunsmith's tell me not to use the SP from Hornady. I shot a box in my wifes 243 and couldn't get them to group either. I would also look at your scope or mounts. Something isn't right eitherway. Try another brand of ammo. What one gun shoots,another hates. That gun should shoot better than that. All ese fails,call Tikka. I hear their customer service is top notch.