Snipers and cover saves

After having a sniper go spastic and kill a ton of US airborne last night (obviously a grizzled Stalingrad veteran), I had an epiphany I might be playing the rules wrong.

According to rules a sniper's target counts as in open terrain for purposes of shooting. Does that mean it's cover save is reduced to 6+ or does it retain its original cover save but is just easier to hit?

Cover save is 6

Thanks Piers.