I have a Saiga 12 that I have not done any modifications on and had the receiver cover pop off while shooting (doesn't happen all the time, seems when firing higher magnum shells and the gas port is on 1). The retracting mechanism plunger is up to hold the cover in place but it still popped off. The issue appears to be that the front of the receiver cover where it is slides under in the slot, by the front sight/tube and end piece, is less then 1/32 of an inch or less even though it can slide up about 1/16 inch. How can I fix this? Not sure how to keep the receiver cover slid on tighter. Any help would be great.