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.