I don't think the accuracy change has to do with cleaning. I have cleaned the same way, wd-40 and nylon brush along with patches for several years on this gun. It's never been an issue in the past. Tensioning he breech unevenly is possible and I will see if I did that. But the trigger is engaging at all times it doesn't auto close/fire and I'm unsure that would cause the weak valve strikes. If it was just a poi shift I would think it could be the barrel bands..but it appears to be more than that.
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