Hand-to-hand-combat range.
Not much to tell here. In warfare there's not much space to kill with bare hands. Soldiers have weapons and they reluctant to use even those. We could check murders but most of them are committed with other "tools" and these cases were mostly committed by those 2% anyway. And fistfights, wrestling, beatings aren't this category.
It's not easy causing significant damage with just hand-to-hand. Grossman mentions two possibilities: punch in the throat and a thumb into the eye and the brain (his description isn't big on the details).
Man has a tremendous resistance to killing effectively with his bare hands. When man first picked up a club or a rock and killed his fellow man, he gained more than mechanical energy and mechanical leverage. He also gained psychological energy and psychological leverage that was every bit as necessary in the killing process.