Been away from the thread since Friday
It grew a bit.
Gscholz, that website you posted the link too is a direct rip off of the information written in Istvan Toperczer's books, of which I own all 4. He is the original author of that information. Best books written from the NVPAF perspective.
As Funked said, if you want incredible information on how the airwar was fought over North Vietnam, get "Clashes". Incredible book, with a detail investigation into how and why the war was fought the way it was. Best out there.
A couple of points I saw mentioned in the thread.
The only internal gunned F-4 was the USAF F-4E. Gunpods were available to all the services flying them, but they were extremely unpopular. They added something like 20% to the drag of the aircraft, and weighed in the neighborhood of 2,000 lbs. They also had a propensity to jam after the first couple of rounds, leaving you with a perfectly good brick attached to your plane. The Navy almost never used them. The Marines used them for ground attack missions. And the Air Force used them sparingly, depending on the squadron and the wing, the planes were assigned too.
A myth about the gunpods, is that they were that they were horribley inaccurate. Not totally true. The nose gun mount on a F-4 (and I believe the F-105 is similar) has a dispersion of approximately 5 mils. The gun pods had a dispersion of 6-8 mils. True, thats more. But with a weapon like the GE M61 Vulcan cannon (20mm) dispersion is NOT a bad thing. The weapon has a rate of fire of around 6,000 rpm, and a average amount of dispersion means its easier to hit, and means lots of bits and pieces of the enemy is getting hit simultaneously. Its like hitting a rioter with a firehose.
I've seen guncamera footage of a F-105D (same gun) shooting down a MiG-17 with its gun. As soon as the pilot pressed the trigger, the entire MiG airframe looked like a Christmas tree that was flicker on and off. It was in slow motion, but it couldn't have been more than a 1 to 1.5 second burst, and within that time, not one single portion of that airframe did not get seriously hit. The MiG simply disintegrated.
The problem with getting gun kills during Vietnam for the US was in my opinon due to training and poor air to air gunsights. The pilots had mostly been trained in the belief that missiles made guns obsolete. And in the early F-4 (the B and C's) and F-105's, the gunsights were simple fixed sights. It wasn't until later models that they added air to air lead computing gunsights to the aircraft. Something that had been added to P-51 during the last months of WWII.