A bit yeah, but it's still infinite ammo so yes. One is infinite the other is burst. Icebreaker you can burst around 7-8 shots before having to wait on more ammo. Black Hammer you can burst 18 shots without having to reload or wait for ammo. So Black Hammer is still the weapon for burst dps and Ice Breaker the weapon for longer periods of damage where perhaps you can't stand there freely shooting the boss.