It may be one of the above or it may be the factory ammo not suiting the barrel. I'd re-check nothing's loose, remove the action to check bedding, replace and re-torque bolts, clean the barrel (if used, it pays to do a deep carbon clean to eliminate any carbon rings which may be close to the throat), then after a few cold bore shots, chose the ammo you used for the 1" group and try a few 5 shot groups leaving a minute or so between each shot. Worth also bearing in mind gun fit. If you don't take the same cheek weld position every single time, you'e going to throw your groups off. Also concentrate on trigger technique. Dry fire a number of rounds keeping your eye on target and not altering cheek position. Ensure you're not gripping the grip too tightly as this can throw shots off. Just your thumb bracing the grip from behind with a loose grip to the trigger finger and using just the front finger pad, ensure you're squeezing consistently so that the trigger break is consistent...don't pull the shot. If all of that fails, you may want to try other factory brands on ammo that suit the rifle and stick with them. Worth also checking the scope mounts and doing a scope tracking tall target test to ensure it's not a scope issue.