I have a problem with scope walk on my .22 Marlin model 60. I have tightened it as tight as it will go but after firing a number of rounds I have to loosen my scope (Bushnell) and move it forward back into position. I tried some black silicone in the groove but it was a temporary fix. After a short time the scope would push it out of the narrow channel and start walking again. Should I use an epoxy? I'm considering using a punch and pinging the back of the scope mount on the rifle but I don't want to marr the gun. Do you have any suggestions on how to prevent this?