Hathcock set the record for the longest confirmed kill at 2286 metres in Vietnam, 1962, which lasted for 40 years.
Your question is a bit ambiguous, so I'll go with the notion you're referring to the longest confirmed kill by a sniper. That was achieved with a rifle chambered in .338 Lapua Magnum.
The 2Nd longest sniper Shot ever taken place was By a Canadian sniper on tour in Afghanistan, rack up two kills from about 2.5miles! and finally the farthest sniper kill was from a British solider also on tour in Afghanistan taking a life at about 3.1miles!
Top Shot - 2010 The Longest Shot 4-9 was released on: USA: 10 April 2012
The longest shot he has ever taken was 9,892 miles from Japan to Saudi Arabia.
It was confirmed on the radio and news that Kevin Jonas was shot.
L115A3, otherwise known as the Accuracy International Arctic Warfare. It fires the 8.58x70 cartridge (also known as .338 Lapua Magnum), and the shots made actually exceeded the projected range of the rifle.
There is no video of it. You can't watch it.
Not yet confirmed?
200 yards
Infinity yards
the answer is 200ft!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!