I don't know if this happens to others, but I feel, sometimes, you just have a strange day at the range.
I was shooting my SW 460 last weekend. It has been my go to gun recently and has never given me any issues. This weekend my first three shots were horrible. I even had to adjust my scope some. At first I thought I had blown the scope. After some shooting I had about 15 shots that were spot on.
I am not ruling out that the scope isn't going out but I have no explanation as to why the gun, which has been my trusty wheel gun, gave me so many issues.