Black Hammer has the potential to have unlimited ammo, which is an exotic-level perk. It should not be on a legendary-tier gun. With the way they are changing it, White Nail now becomes a better version of the Triple Tap perk (full mag reload vs 1 round) which is more appropriate for a raid weapon. As a legendary, Black Hammer also will not be upgradeable to the Year 2 damage cap, so it's not like it really matters. I think the Ice Breaker nerf is way more unnecessary.