Yes i have.
Though the trick is to shoot snipers in the body once, so that they are less likely to run back to spawn for health. Then headshot them after to get the kill. Head shotting people first usually scares them away.
ambassador headshot does 100 damage, snipers have 125hp. A headshot wont kill them unless they are already damaged by spam/other snipers. Hence the need to put a bullet into their body first do trim the ~25hp off before getting the headshot kill.
headshotting first takes their health from 125 to ~25 and so they will probably run for health, whilst if they only took ~25 they'll probably stick around a bit longer.
Real men flaresnipe.