I bought a used 1V some time back, with blocks and rings but no scope. I had a low power scope on it for a while, then recently changed to a higher powered scope with a considerably smaller range of adjustment. The point of impact is a couple of feet low and about three feet to one side when I run out of adjustment on the scope. It was far enough off that I never bothered firing the gun, because I could see the difference merely by looking down the bore with the breech open.
When I removed the rings and looked at the blocks, it looked like the rear one was lower and to one side of the forward one. A straightedge placed across the top and one side of the front block appears to confirm this. The gap that shows on each measurement may be as much as .050". The rear mount appears to be parallel to the front, merely displaced down and to one side.
I made an effort to remove the screws on the rear mounts, but they are more than likely locked in either by age or loctite.
Before I go any further, and risk breaking off the screws, I would like some opinions. First, am I on the right track in suspecting the blocks?
Second, are there other mounting systems than the Ruger that I should consider? I have a very vague memory of a mention somewhere that Ruger had a problem with the mounts on the 1V at one point in time. I didn't own one at the time, so I don't remember any details.