This was sort of an experiment done during the Vietnam war. I am going from memory here but IIRC, the scope is a Unerlt that was issued to Marine Snipers. In 1967, Carlos Hathcock made a 2,50 hundred yard kill with that configuration a record that stood unbroken until 2002. I think the gentleman serving as spotter is no other than Jim Land who founded the new Marine Sniper course. Amazingly, no branch of the US military had an active Sniper course or snipers available until they were needed in combat and then they had to start from zero as the thought of snipers was not palatable to the Regular Military.