The actual bullet in question is the Sierra Match King 168 grain HOLLOW POINT Boat Tail Spitzer. There is a clause, and there may be several clauses, in the Geneva Convention the forbids the use of hollow point bullets, or other bullets specifically designed to cause more grievous wounds. This includes "dum-dums" or explosive type bullets as well as hollow points.
However, the bullet in question is NOT a true hollow point, in that there is not an actual large cavity designed do hydraulicly expand. The reason for the small opening in the bullet is to allow it to be manufactured and loaded (Federal uses the bullet in question in their Match Grade .308 ammo, specified by the FBI for sniper use) without damaging the bullet and causing it to be inaccurate.
I keep a couple of boxes of those bullets, I use them in ALL my 30 caliber rifle loads. They are indeed the most accurate 30 caliber bullet available, by a large margin. They DO NOT expand like a true hollow point.
Several of the military competition shooting teams use the same bullet in their match ammo, whether it is loaded in 308 or in 300 Winchester Magnum cartridges.
I actually have some of the military sniper ammo for a 300 Winchester Magnum in my cabinet. It is not even as hot as my own loads, but it is quite accurate, though not as accurate in my rifle as my hotter loads.
There are plenty of other bullets that could be used if the intent was to use a bullet that caused more tissue damage. That bullet was chosen strictly for accuaracy, and anyone who has used it or knows weapons and ammo would know that. The advantage it has for using it to kill things is SHOT PLACEMENT. Few bullets are capable of 1/4 MOA accuracy, but that one is.