This is a modification that I created to take better advantage of what accuracy potential the AK may have with a receiver sight. First I want to say, If you are skeptical about or don't think my idea will work, simply don't do it. I have it in use on 3 of my AK's and so far it has worked great. I use AR15 windage adjustable sights because I like being to adjust windage with the big click detented adjustment knob. You can use the sight of your choice but height from the receiver cover is important. It is preferable to try to keep the original AK sight height if possible. I bought an extra receiver cover and recoil assembly for the rifles that I put this mod on. If I decide to sell the guns later on, the buyer may want the gun original, so I can convert it back to the original rear open sight, and recoil assembly in a matter of seconds. I use small countersunk screws and epoxy to mount the sight to the receiver cover. In try to mount the receiver sight in a position so that when looking through the aperature, you see normal open front and rear sight alignment before removing the rear open sight. The receiver cover to be used for this must be made to fit the receiver very well. The edge that fits in the rear "trunion" groove must be absolutely flat and not be able to rock sideways. The sides of the cover near the back must fit the receiver snugly, but not tight. Without the recoil spring assembly installedassembly installed, you should be able to fully seat the cover down with no more than light finger pressure, and have no side to side movement. Next, you need to install a "U" shaped piece of 1MM sheet metal over the bottom edge of the locking button hole in the receiver cover. The pic shows what I am talking about. This piece should be epoxied in place. This acts as a bearing surface for the modified locking button on the recoil assembly to push down on. The side profile of the locking button needs to be cut or filed so that it has a ramp on the bottom as in the pic. I measure about 3/32" from the bottom of the button and scribe a line from that point to where the button intersects the body of the recoil cover lock assembly. As the recoil spring pushes back, the ramp on the bottom of the locking button pushes down and back on the receiver cover. Providing there is no side to side movement in your cover, it cannot help but return to the same place when it is reassembled on the rifle. The target was shot with my Yugo M90 with cheap (relatively) American Eagle 55 gr. FMJ. I shot a five shot group, marked the holes, removed and replaced the receiver cover and shot another five shot group. It was shot at 50 yds. with extreme spread of the 10 shots being 1.42"