The Problem with Gunbreaker, short and simple.

[Arohk]

#Skillspeed reduces the Global Cooldown of Weaponskills.
#Skillspeed reduces the cooldown of certain abilities to compensate for that.
#Skillspeed DOES NOT reduce the cooldown of "No mercy".

this causes unclean rotations with 600+ Skillspeed (2.47 sec. gcd)

All BiS tankgear gets you above 600 Skillspeed.

Solution:
Skillspeed must also reduce the cooldown of "No Mercy" to be in line with "Sonic Break" & "Bow Shock"

[Absurdity]

GnB has quite a few issues, this is such a minor one that I'm reluctant to even call it an issue. It simply means that your No Mercy windows aren't a static sequence of the same 9 GCDs every time but it shifts slightly every 60 seconds until it loops back to your 1 minute No Mercy again after about 6 minutes.

You still have 6 GCDs that happen during every NM window, Gnashing Fang*, Double Down, Sonic Break, Savage Claw, Wicked Talon and atleast 1 Burst Strike, the other 3 GCDs and the order in which you execute them however is fluid. It is simply a learning experience to know on which GCD you start your No Mercy window.

*Gnashing Fang is a bit of an exception because your 3 minute and 9 minute Bloodfest+NM burst starts after Gnashing. This is a mostly a potency issue, because for some reason SE decided to make Burst Strike a 20 potency gain over Gnashing Fang, making it more optimal to put an extra Burst Strike in your buff window instead of Gnashing Fang.




The much bigger problems are repositioning bosses during Continuation due to it's incredibly limited range, on top of the increased frequency due to the addition of Hypervelocity, and the fact that No Mercy did not see an increase in duration from ShB to EW despite GnB gaining more forced oGCDs, resulting in your last Hypervelocity falling outside of your buff window almost every time.

Both issues can easily be fixed by increasing Jugular Rip's, Abdomen Tear's, Eye Gouge's and Hypervelocity's range from 3 to atleast 6 yalms and extending NM from 20 seconds to 21-22.

[Crater]

This is a hidden strength of Gunbreaker, not a weakness or problem. It means that, while No Mercy is on a strict cooldown, you have some latitude to delay Gnashing Fang, Double Down, and Sonic Break by some amount if necessary/forced and they will gradually re-align themselves as the fight goes on.

Obviously that won't come up during an optimized run where your GCDs are known beforehand, usually won't have much effect, if any, in a run where everything goes smoothly and according to plan, et cetera, but part of the reason Gunbreaker tends to have a more smooth play experience than other tanks is that the effect of Skill Speed on its GCD Cooldowns causes its rotation to self-repair a lot of minor mistakes in a way that you don't get on Paladin or Dark Knight.

[Arohk]

I think you're not understanding the issue i'm pointing out, the entire gunbreaker rotation lasts exactly one minute from one No Mercy to the next, but if you have too much skillspeed, you lower that time from 60 seconds to below 59 seconds, then you end up with 3 Erda and have to wait for no mercy to be ready or spend one Erda on Burst strike or waste one Erda by using solid Barrel because you're one global CD too fast.

[Hierro]

I just clip gcds with blasting zone. Keeps me in line enough

[Ryaduera]

If no mercy lasts less than 60s it falls out of line with raid buffs, which is a DPS loss in most parties and in most encounters, so you don't want that since you'd be forced to drift it anyway just to keep in line with raid buffs. The solution is to use 1 more GCD or clip slightly, drifting your GN/DD by just 1 or less GCD. You'd still be doing that to align with raid buffs even if you had the extra cooldown on NM.

[Kromulus]

I think you're not understanding the issue i'm pointing out, the entire gunbreaker rotation lasts exactly one minute from one No Mercy to the next, but if you have too much skillspeed, you lower that time from 60 seconds to below 59 seconds, then you end up with 3 Erda and have to wait for no mercy to be ready or spend one Erda on Burst strike or waste one Erda by using solid Barrel because you're one global CD too fast.

the rotation of GNB does not ever loop in a fight. ever. the rotation every 60 seconds including the exact weaponskills used both in and out of NM are different. while the initial Gnashing, Double Down, Sonic Break, Savage Claw, and Wicked Talon may always be placed the same in the No Mercy burst, the placement of a Burst Strike in NM will change, the combo actions used change, Bloodfest exists which should be used on cooldown, it will never be the same thing per minute.

also, the only affected SKS actions are Gnashing Fang, Double Down, and Sonic Break, not "Bow Shock" as you stated before.
there are no abilities affected by SKS, only weaponskills.

the goal of the rotation is to attain 3/3 cartridges and utilize GF's combo, Double Down, Sonic, Burst Strike to its maximum possible quantity, and then combo from there inside No Mercy. outside of No Mercy, you are building to 3/3 cartridges while keeping Gnashing Fang and Blasting Zone on CD to maximize their usages, and preventing cartridge overcap by using Burst Strike when you are about to overcap. overcapping is a detrimental loss and should be avoided. there is never a scenario where you need to overcap.

not to mention, by going with a GCD tier that is faster than 2.47, you gain a GCD under No Mercy. the damage calculation is determined from the moment an ability is used, and being faster than 2.47 allows you to fit a ninth GCD inside of NM and have NM's damage buff apply to it. going slower than 2.47 will only cause you to guarantee yourself to lose a GCD inside of NM.

there is nothing unclean about the rotation, you just have Gnashing, Double Down, and Sonic reverse drift and come up earlier and you just hold it by one GCD to push it back into No Mercy.
you'll encounter situations where you are 3/3 cartridges with Solid Barrel ready and NM will not be ready until the next GCD, in which is the only time you use Gnashing before No Mercy as that's the only action available to not delay NM and not scuff your burst window. this is what is known as a GFNM window. it happens under 123NM at 3 minutes, 5 minutes, and 10 minutes.

if you're interested in learning more, please seek out Rin's 12 minute GNB rotation and 123NM opener.
https://www.youtube.com/watch?v=Seua-yrZC6s