This. You can continually unload on a Boss with the hammer as long as you crit them and most bosses aren't that hard to do that on. Ice breaker you might be able to get 8-10 shots steady but will find yourself firing at an incredibly slow pace to keep from going empty. Black hammer you can put 30 shots into a boss in the same amount of time. I loved Ice Breaker, have one on each character. I haven't touched it since I got the Black Hammer about a month ago, actually I did, I used it to regen ammo during a nightfall since I was out of special and then switched to my black hammer to do the job. It's more of an exotic that Ice breaker is and with the same burn its a better choice.