I recently broke my Gamo whisper fusion mach 1.177 and was so disappointed I thought it was gonna be spare parts untile I noticed that the benjamin prowler .22 cal barrel and cocking arm fit so nicely in place of the original barrel. I removed the shroud and couldn't be happier. Converted from .177 to .22 cal and it almost hits just as hard as my Gamo swarm Magnum gen 2. Gun on top is
A benjamin prowler and gun on bottom is Gamo with prowler barrel!

A benjamin prowler and gun on bottom is Gamo with prowler barrel!