I recently posted this to /r/GunsOfIcarusOnline, and I thought it would also be a good idea to post it here.

Way back when I first started GoI, I heard a rumor that Heatsink rounds where better for the gats than greased. I continued to use greased however, because that is what everyone else used. But I never forgot that first rumor. So today, I did the math.

I'll start off with the default values taken from the GoI wiki:

Dmg = 17.5

RoF = 8.33 b/s

Size = 82

Reload Time = 5s

We'll begin with greased:

+60% RoF = 13.33

+20% Size = 98

-20% Dmg = 14

(Size / Rof) * dmg

(98 / 13.33) * 14 = 102.93 Dmg/s

Now for heatsink:

+30% Size = 107

-17% Dmg = 14.53

(107 / 8.33) * 14.53 = 186.64 Dmg/s

So there is a big difference there, but there is the reload time to factor in. And we can factor that in easy. To find how long it takes to empty a clip, we can divide the size by the rate of fire. Then take the highest of the two, divided it by the lowest + reload time, and get a ratio between them.

(107/8.33) = 12.85

(98/13.33) = 7.35 + 5 = 12.35

12.85 / 12.35 = 1.04

So the greased round will become multiplied by 1.04 because it will finish off 4% of the next clip by the time the heatsink finishes its first.

102.93 * 1.04 = 107.05 Dmg / s

The gat with a heatsink round will do 186.64 Dmg / s, and a gat with greased rounds will do 107.05 Dmg / s. Making the heatsink 74.3% more effective than greased.

Also, if we instead take the amount of dmg / s in the same amount of time as the finishing of a greased round clip, it ends up being 106.38 dmg / s for heatsink. So it is still more either way, but by a considerably smaller margin. Only about 3% improvement.

Aside from the increased dmg / s, heatsink rounds also include a +50% bonus in rotation speed, making it much faster to get on target. And finally, it is also immune to fire as long as the ammo is currently loaded.

TL;DR: Heatsink is 3%-75% more effective than greased at any given time, with the added tactical advantage of faster rotation speed and immunity to fire.