In the Marines it's 500m, but the target stays up longer. Even with that, on a calm day about 5% of the shooters will be scoring head shots consistently at that range. And no, this isn't specialized units. This is with whoever has to qualify that month. This isn't even really bragging (too much)[1]. Having been through the training, I'm confident they can teach just about anyone who really wants to learn to do the same in about two weeks.
[1] If I can rest my elbows on something I'm good for consistent head shots at 300m, body shots at 500. But make me stand up and just hold it, I might as well throw the rounds down range for all the good it does me. Apparently the hands are steady, the body ... not so much.