Tried out the new scope on the Remington Nylon 66 last weekend. Carefully held the gun up with one hand and made adjustments with the other until the holes were appearing exactly under the cross hairs. Put the gun down on the soft case on the table and changed targets. Put up one featuring 3 rows of bowling pins on an 8-1/2 x 11 paper. First shot to the upper left hand pin barely touched the edge of the paper. Second shot to pin #2 hit pin #1 dead center. How odd.
I worked my way across the target, left to right and started the second row when I noticed the holes were moving to the right. By the time I got to the last pin, the holes were appearing right under the cross hairs again.
Note to self: Once you've got the sights zeroed, be sure and store the gun under cover or at least in the shade. It doesn't seem to like extended periods of direct sunlight on one side.