Like most of the other guys stated this is a big difference. If the bore butter trick doesn't work, the only alternative you have is to sight in with a clean barrel. It would be nice if you had someone to help you.
Shoot the first shot out of the clean barrel being extremely careful your sight picture was correct. Then with you holding the rifle steady on the rest with the crosshairs on the bull, have your friend adjust the crosshairs to the bullet hole without you moving the rifle. Now, give it a good cleaing. The same as you would at home.
Try the shot again. Hopefully it will be on target.Normally we only get one shot. So why go through the hassle of fouling a bore nad worrying about corrosion when we can shoot from a clean barrel with good results?
Hope you get this problem resolved.