MJB,
That question is more pertinent than one thinks....unless the rounds impact something of stoutness....such as main beams, or other heavy duty structural members....perhaps not. The distance between the point where the round impacts and the pilot also plays a role in whether it is felt/heard/recorded.
That being said....when a .51 Caliber round removes the pedal from under ones foot....trust there is no doubt that it has passed through the cockpit! However...there can be great uncertainty as to exactly what has occurred despite there being no doubt it is not for the good!