I have one of these rifles, and I am finding that even by changing rings and scopes, I can’t get the adjustment up enough to keep from hitting 12 to 14 inches low at 25 yards. The .22 caliber rifle was pretty much in the bottom of the pile, until I noticed some posted in a different forum about the same thing about the exact rifle that they own . They posted later that they placed a shim under a base and fixed the problem. Is that a kosher fix ? Wouldn’t that indicate a barrel not concentric to the receiver bore ? Would that cause problems at different distances? I trust you precision guys on this. Shimming a base to a receiver to get scope alignment seems like a baling wire and scotch tape approach.