Its depends largley on skill. In 2 equaly skilled players hands the black hammer will be a more efficient harder hitting weapon. Ice breakers ammo regen is good but when both players are hitting only headshots, the higher impact and white nail perk make black hammer more efficient. Now if both players are bad at sniping then ice breakers regen and muligan would compensate for shots missed. Making it a more forgiving gun for unskilled players.