It doesn't need to be any more than what it (apparently) says on the tin. .50 BMG is very ballistically efficient as it is, so at shorter ranges, windage really

It doesn't need to be any more than what it (apparently) says on the tin. .50 BMG is very ballistically efficient as it is, so at shorter ranges, windage really isn't much of a concern. But at a couple of kilometres or more, drift can be significant. Keep in mind that these bullets will be used for individual kills of high-value human targets (no point putting it any differently; there's no advantage over tracers when used for automatic fire for antimateriel purposes where single shots would be ridiculous to contemplate, and there's no "shoot to wound" in the military, both by the rules of war and for more practical "he can still shoot back" reasons), and that recent operations (particularly in Afghanistan) have been in conditions where trying to get closer than a couple of clicks is suicidal due to lack of cover.