Here is the pictures of both the .177 CFX's
The one with the longer Muzzle brake is the Walther barreled version. Had to make a new brake for it because the barrel is 1/2 inch shorter than the cocking lever, it still has 17" of rifling but does not have the turned down end like the standard barrel. This is why it's shorter than stock. It has a chamber in the brake and came out real quiet.