Woah there fella! I know you're hurting, but there's no need for that kind of language.

Icebreaker's a pretty cool gun, and there's a lot of anger and upset at the moment about the coming update and how it's going to be affected. And don't get me wrong, I'm not gonna sit here and tell you they haven't nerfed it or anything like that. But looking at their stated goals, and the specific mechanics for No Backpack, I think the Icebreaker nerf is actually pretty damn clever.

Oh, and don't worry. There will be maths.

The Nerf
So in case you don't know yet, Icebreaker is being nerfed. But not in the conventional sense that Auto Rifles or the Mythoclast were nerfed. Icebreaker won't deal reduced damage, it isn't going to be harder to aim, and it will still make that cool-ass 'pseew, pseew' noise.

Instead, the No Backpack perk is being changed. Instead of regenerating a single round of ammunition every 5 seconds, it will take 8. That might sound like a lot (60% longer!), but because the base stats haven't been changed, the difference is less than you might think.

Burst DpS vs. Sustained DpS
Because the base stats are unchanged, an Icebreaker 2.0 with a full magazine of 6 rounds will deal exactly the same damage as the OG Icebreaker. The burst DpS is the same - if you're picking on single targets here and there or unloading a few quick rounds into a Major Knight's face, nothing much will change.

But what about when you empty your magazine? That's when the nerf comes into play. The longer recharge time reduces your Sustained DpS, with the effect of the nerf working on a sliding scale - the more rounds you wait for, the more pronounced the nerf, starting at 0% and trending towards 37.5%.

Some benchmarks:

• 0 Seconds: 6 shots vs. 6 Shots - 0% Nerf
  
• 40 Seconds: 14 shots vs. 11 shots - 21.4% Nerf
  
• 80 Seconds: 22 Shots vs. 16 Shots - 27.2% Nerf
  
• 120 Seconds: 30 Shots vs. 21 Shots - 30% Nerf
  
• 160 Seconds: 38 Shots vs. 26 Shots - 31.5% Nerf
  
• 400 Seconds: 86 Shots vs. 56 Shots - 34.88% Nerf

As you can see, the longer you're stood with your Icebreaker out, waiting for ammo, the worse the nerf will affect you, and the poorer your sustained DpS will be.

The Clever Bit
"But that's not very clever", I hear you say. "They've just increased the Reload Time. That would decrease the sustained DpS of any weapon". And it's true for every other weapon - imagine if they doubled the Reload Time of Gjallarhorn?* Just a direct Sustained DpS dropoff because of all that time spent reloading.

"But that's the clever part" I say.

Icebreaker's signiature perk (the real one, because we all know it's not 'Icebreaker') No Backpack regenerates ammunition passively. Where slower reloads on any other weapon would cause your sustained DpS to drop off permanently because they need to be reloaded before you can use them again, Icebreaker will refill itself while you switch to another weapon.

Instead of waiting around with your Icebreaker scoped in, wasting potential DpS, you can switch to your other weapon, keep firing (and keeping your DpS up), then come back to a gun that's miraculously reloaded itself.

If you use your Icebreaker in bursts, instead of trying to use it as your primary and only source of damage:
A)This nerf won't affect you
B)Your DpS will actually increase!

And what have Bungie said in regards to this nerf?

We’ve all done it. Hunker down in the back of the map with your lunch box, picnic table, a sci-fi paperback, and Ice Breaker. Kill all the enemies, wait for more to show up, kill those ones too, put a few shots on the boss, make a sandwich, finish the strike, and then collect your reward-that-isn’t-Hawkmoon and move on.

[...] a really great thing happens when all of a sudden you need Ice Breaker and you’re still waiting on that next round to show up. In that moment there is an interesting tension at play; you need to think about how you spend your next few seconds while it recharges. We are going to amplify that tension by increasing the recharge duration by a few seconds.

Yep. Their goals are to prevent you from sitting at a safe distance plinking away at the enemy, and to make you think about your actions in the downtime between ammo regen. Well now if you want to maintain your DpS you need to be utilising that downtime better, and to do that you need to be closer to the action. Check and check.

Pretty clever, if you ask me.