Describe the issue
Mr. CrayFish's gun mod adds a swaying animation that appears to completely mess up the camera for your mod.

Can you add a video showing the broken movement?

I don't know enough about the camera roll stuff to make these two compatible but here is my issue report for their mod (I'm really only sending this here so it pops up on the other issue page) : MrCrayfish/MrCrayfishGunMod#431

You might not be able to tell but the camera is moving quickly in direction when I'm trying to smoothly turn

It's hard to tell unless you play and try it yourself.

Do you have optifine installed?

Optifine is not installed but I do have a couple of forge performance mods installed.

I don't see how, but I also don't see any code in the gun mod that could conflict. Forge is not a primary supported platform due to my limited knowledge of it, so you're probably better off looking for a fix on gun mod's side.

Do you think any of those performance mods are the culprit?