Rotating arm at a pivot point

Im making a gun system with no view models and ive almost got it but the arms won’t rotate at the correct pivot point.

I made your head follow your camera, and positioned the camera where the characters eyes would be. This is important because it keeps your arms in the same spot in your screen as you look up and down the same way a view model would. But in the animation you can tell I moved the arms forward, so this doesn’t work anymore unless I can get it to rotate from the same pivot point.

I want it to rotate from the green dot (where the arm is when no animation is playing), but it rotates from the red dot (the pivot point of the motor6D). I know I’ll have to change the cframe with an offset but I don’t know how to get that offset. Im using the transform property to make your arms follow your camera (lmk if there’s a better way to do that but I already tried C0 and C1)

I will provide code if needed and it was kinda hard to explain this so tell me if it makes no sense