I have a Whisper Fusion that can't hold a zero on any scope I've tested. I have determined it isn't the scope. The barrel in my gun has a weak "detent." The barrel detent clicks shut when you close the barrel and holds it tightly closed. My barrel has a lot of wiggle in the same direction as the barrel pivots. There is near zero side to side wiggle, but the "up and down" floppiness was terrible.How does your gun close?
Most of the package scopes/mounts that come with the Gamo Guns will not hold up to the dual recoil. I recommend an Air Gun rated shock proof scope with a one piece scope mount for all spring guns...You can get a 30mm one piece scope mount for the bug buster on Amazon.For guns that do not have good scopes already look at the Hammers 3-9x40 on Amazon.