As in the discussion of some major WWII fighters, these aircraft are sorted by fired mass per second. The muzzle power is also given, in kilowatt.

North American
F-86A Sabre

The F-86A was the first American swept-wing jet fighter, a development of the Navy’s straight-wing FJ Fury based on German research. It was inferior to the MiG-15 in climb, in service ceiling, and in speed above 20,000 ft. But the Sabre had a good performance at lower altitudes and much better handling characteristics at high speeds. Better pilot training gave the USAAF the upper hand in its fight against the MiGs.

It carried six Browning .50 M3 machineguns in the nose, with 267 rounds per gun. The M3 version of the venerable Browning fired at 1200 rpm, so the Sabre could fire 120 rounds per second for 13 seconds. This gave a weight of fire of 5.8 kg/sec. The muzzle power was 2203 kW. 

Identical armament was installed in the Lockheed P-80 Shooting Star (with 300 rounds per gun) and the Republic F-84 Thunderjet. In terms of weight of fire and muzzle power it was not so bad; but the during the Korean war it became clear that the .50 projectile was inadequate against the sturdy and well-armoured MiG-15. Many MiG-15s returned to base despite numerous hits. Four 20 mm cannon were installed in a few Sabres for combat evaluation, but only after the Korean war did these weapons become standard armament on USAAF fighters. 

Grumman F9F Panther

The US Navy was eager to get jet-powered fighters, despite the disadvantage of early jet engines for carrier operations. Neither the Vought F6U or the North American FJ-1 could be considered successful, and the McDonnell FH Phantom was soon succeeded by the F2H Banshee. The Grumman F9F was a fairly conventional design with a straight wing, but it was reliable and rugged and a good fighter-bomber. Although the F9F was outclassed by the new generation of swept-wing fighters, the first jet-versus-jet combat ended when a F9F-2 shot down a MiG-15. There is some irony in the fact that the J42 engine of the F9F-2 was a version of the Rolls-Royce Nene, just like the VK-1 of the MiG-15!

Four 20mm Hispano M3 cannon were installed in the nose, with 190 rounds per gun. The F9F fired 57 rounds per second, a weight of 7.4 kg/sec. Total muzzle power was 2660 kW. It had ammunition for 13 seconds. 

This was the best armament combination then available, considerably more destructive than the .50s of the F-86 and without the disadvantages of trajectory and harmonisation of the MiG-15. But the foresight of the USN in the selection of armament was balanced by its conservative approach to aircraft design. The McDonnell F2H Banshee and the Gloster Meteor (operated in Korea by the RAAF) had the same armament as the F9F, and they too were used mainly for ground support operations. Grumman developed the swept-wing Cougar from the Panther, but the type was too late to see combat in Korea. 

Mikoyan-Gurevich MiG-15

The MiG-15 shocked Western complacency when in appeared in combat over Korea. The engine had British origins and the aerodynamics were inspired by German research, but nevertheless it was a powerful reminder that the USSR had an advanced aviation industry. The MiG-15 had a higher service ceiling than the F-86, outclimbed it and was faster at high altitude. It’s handling characteristics left something to be desired and it could be dangerous for less experienced pilots. Aerodynamic flaws were corrected in the MiG-17.

Late-production MiG-15s and the MiG-15bis had one 37mm N-37 cannon with 40 rounds and two 23mm NR-23 cannon with 80 rounds per gun. (Early production MiG-15s had NS-23 guns with about half the rate of fire of the NR-23.) The neat weapons tray under the nose could be lowered for reloading and maintance.

The MiG-15bis fired seven 37 mm and twenty-eight 23 mm rounds, with a weight of fire of 10.7 kg/sec and a muzzle power of 1872 kW. The ammunition was expended in six seconds. 

The MiG-15 represented an approach to fighter armament that was totally different from that of the F-86: Big guns with a modest (690 m/sec) muzzle velocity, firing rounds with a very high destructive power. This armament had been devised to destroy bombers such as the B-29, and the MiG-15 very effective in that role. The USAAF was forced to call a halt to daylight B-29 operations. But for use against fighters this armament suite was less ideal; it mixed guns that were a poor ballistics match. In addition, the MiG-15 was a mediocre gun platform and had an inferior gunsight. 

Comparison Table

Name	Rounds (per sec)	Weight (kg/sec)	Energy (kW)
North American F-86A Sabre	120	5.8	2203
Mikoyan-Gurevich MiG-15	22	5.8	1066
Grumman F9F Panther	57	7.4	2660
Mikoyan-Gurevich MiG-15bis	35	10.7	1872

Beyond doubt the best armament in use consisted of four Hispano cannon, in either the American M3 or the British Mk.V version. This offered both high destructive power and a high muzzle velocity. But the two best fighters of the war were the F-86 and the MiG-15: The armament of the first had a high muzzle velocity but was deficient in destructive power, and for the second the reverse was true.