I really hate GNB with 3 carts and Double Down taking 2 carts

[Mithron]

Why would you ever use gnashing fang vefore no mercy? I know it's supposed to be used on cooldown, but if you're placing it right, it should always be up in time to fit within a no mercy window.

I really dislike how slow the gcd overall is in Endwalker so far, but even at my slowest of 2.47s I was able to fit all my cartridge spenders in it. Although I never used them in the order most folks would say to.

Because with your second Bloodfest, you need to use No Mercy after Gnashing Fang to fit more Hypervelocities in which is greater DPS gain. You can even see it in the picture posted above.

When you're doing your rotation right, No Mercy and Gnashing Fang will inevitably sometimes not line up correctly at level 90.

As per The Balance GNB guide:

Gnashing Fang ➞ No Mercy

Due to the nature of how Gunbreaker is in Endwalker, if you follow the rotation as intended you will eventually come to a situation at certain intervals where you will have:

Three Cartridges prepped.
Solid Barrel is ready to cast at the next GCD.
No Mercy is still on cooldown until after the next GCD.

This isn’t an error or a mistake, it’s guaranteed in the rotation and will happen. The most optimal choice for this is to use Gnashing Fang ➞ Jugular Rip ➞ No Mercy. (See three minute window above).

Although we are leaving Gnashing Fang and Jugular Rip out of No Mercy, it secures an extra Burst Strike in No Mercy while ensuring that No Mercy does not drift out of raid buffs. It has been discussed and assessed and, as odd as it is, No Mercy after Gnashing is the optimal play and is something you will need to get used to.

It's clunky.