Quote Originally Posted by JGaynor View Post
The John Unertl Company mainly made telescopes for target shooters. The length is a function of the optical system. Another feature is that the adjustments are external and the tube is free to slide in the mounts. When the rifle is fired it moves to the rear leaving the scope forward. The scope must then be pulled back into battery for the next shot.

Jim
Not really....it has a spring that does that!