Chap - That barrel will get better the more it gets shot. But even now you can't complain about that "group". It would have been nice to see just how tight it would have been if you hadn't been raising the sight. It just looks like it was drifting left a little with each shot.
Let us know where it hits with a clean cold barrel next time you take it out.
BTW, mine has been shooting the T/C 275 gr Maxihunters good. I'm casted a bunch of 320 gr REALs to try in it and they shot real good too.