Snipers only load their own rounds in the movies. They get good ammo and if their rifle doesn't shoot it well, they get a different rifle. Much cheaper that way.
I am not a good shot with a rifle.
I use a shotgun, more probability of hitting the target.
Advancements in technology has vastly improved to where the "spotter" can use a scope to tell him exactly to within centimeters the distance to target.
http://www.militaryaerospace.com/ar...er-scope-that-compensates-for-crosswinds.html
Instant wind velocity and elevation available by handheld devices.
All the information needed to calculate and adjust the rifle scope is now immediately available to the spotter.
It still takes skill.. a lot of skill to make a long distance shot.
Give the sniper his just due, he made the shot, he holds the record, luck or skill,it is his title well earned.