IIRC it was that experience with the F4 (and possibly other fighters) in RVN that convinced the powers that be that guns really weren't obsolete, a thought that had some vogue in the late 50's and early 60's when those same PTB figured heat and radar guided air to air missiles had supplanted any need for close in gun fighting.
Gunnery, gunnery, gunnery. Hit the target, all else is twaddle!
