They're right ... closer is better. HOWEVER, if it's an adjustable-power type, sometimes there's a sticky-out bit on the eyepiece. If the scope is somewhat forward, so the eyepiece is over the body of the action, make sure you've got enough room to allow that to turn. Also, you might want at least enough additional clearance to allow for scope covers ... and the flip-up type may need a little more room.
