I usually scrub the bore after every outing.
This gun went from a tack driver to "not in the game at all" very suddenly.
I checked all the mounting screws for the scope after I took it off. Nothing rattles and nothing seems to be loose.
I have the K10 on the rifle now and have it bore sighted. It should be 1 hole groups at 25 yards. Today it was 3.5 inches. That gun has NEVER been that bad.
I will know more Friday.