One other thing it might be.. you mentioned yours was stainless. Sometimes stainless have ruff spots in the barrel. You can shoot them smooth or you can take some J-B Bore Paste and a chunk of Scotch Brite Scrub Pad and buff them smooth. If they are real ruff.. then you can do a gentle lapp on the barrel. Take some cotton balls and push them through the barrel. Then look in there and see how many fibers are sticking to the walls of the rifle. If there are a lot of them, that indicates that the rifle is just ruff and needs to smooth out.

I got two new stainless steel barrels for my Renegade. I was suprised how much better it was after I took J-B Bore Paste and worked the barrel over some. After that the accuracy improved even more...

If you want to shoot them smooth, get a box of cheap maxiball and lube them up, and shoot the whole box off. Then be sure and J-B Bore Paste the barrel to make sure they is no lead build up in it.

I'm sure the scope is mounted right, but check your scope mounts. Also if you put a new scope on it and the rifle does the same thing, then I would suspect that the barrel just needs to be smoothed out.