I mounted my Aimpoint on a riser using the ring it came with. The ring is an extra-wide, two-piece set that is kind of like a clam shell. It is split down the middle vertically. When the screw at the bottom is tightened, the base part tightens to the riser mount. When the top screws are tightened, the ring part tightens around the scope. When all of the screws are tightened, there is still a 1/4" gap between the tops of the ring halves. I tightened the screws until it seemed they were all tight, and the rings were tight to the riser. After shooting it a few times, the scope was loose. The rings had come loose from the riser mount. So, I lossened all the screws and tightened the screw which clamps the mount first. Then I tightened the screws that hold the scope. I hope I got it right this time!

Has this happened to anyone else? Should I get a better ring, like an ARMS or a GGG?

Knights Offset mount