[IvanK]

Having fired both the M61 in the F18 and 2 x DEFA in the Mirage III, and 2 x 7.62 mini Gun on the MB326. I agree with the above post. In the case of the M61 it feels like a fine but noisy Bzzzzz but no head shake whatsoever occurs. In the case of the DEFA (2 x 30mm) its a very rapid pulse (more like a rapid succession of burps) like feeling but again no head shake. Vibration was transferred to the airframe. This could be seen if the gunsight camera mount was tensioned incorrectly. This would result in jittery camera images the next morning when reviewing the cine (A fighter pilot ritual), but to the pilot at the time of firing ... nothing was noticed. Though in all these cases the firing aircraft were a lot heavier and more "densly" constructed compared the the average WWII fighter.

The same goes for general head motion in manoeuvring flight, the pilot compensates posture an eyeball wise the net result is no real issue to maintain a constant sight line. You don't get the "sinking into the pit feeling" you see with track IR at the moment. You know the G is coming on and you compensate for it. In fact body posture control in a fight is an important aspect of fighter flying.