Thirty some years ago I bought a new Nylon 66 and scope. Shooting it without the scope I never really notice an accuracy problem. When I started using the scope I notice the center of impact would change several inches at 30 yards from day to day. If I remember correctly it would shoot OK for a little afternoon fun once I re zeroed it. But the next time I took it back out it would have to be re zeroed again. I took that 22 scope back and exchanged it with another but I still had the same problem. After shooting a few hundred rounds through this gun total and having to re zero it 15 -20 times I packed it away. In talking with my friends, my high school teacher and one of my dad's friends I came across 5 more people that had a scope on their 66 and each one said they had a similar problems. At the time one owner tried a regular rifle scope. Another took the gun to their gunsmith. The gunsmith said he thought it was a problem with the Nylon receiver. Since the rear iron sight is mounted right at the back of barrel the rear sight probably stays pretty consistant with the barrel. The scope mount however is on the nylon receiver. Does the brown nylon stock and receiver move or flex with heat or distort from sunlight from day to day?
If that isn't the problem does this model have a few thousands of an inch to much play between the barrel and receiver that would allow the center of impact to change.
