er... I think it not 137 round for each barrel but 182 rounds for the 4 barrels gatling type 25mm cannon. it not a lot but it take only 1 AP shell to hit enemy plane vital part to shoot it down. while I never fire a gatling gun before but I operated and fired the M242 bushmaster 25mm during reservist. while the rate of fire much slower than the GAU-12/U Equalizer but already the destructive power seen down range was rather impressive.
I think ppl here watch too match WW2 movie, see strafing by bf109, stuka, zeke, p51 etc etc... why would a pilot want to get close to the m&d to strafe with his cannons when he can drop jdam from way high up where he will be safe from hand held missiles? even when the pilot is out of bombs, all he have to do was radio to his AWAC controllers, give the coordinates, type of targets and then hang around where it safe and wait for the arty to rain fire upon the target area.
the F117 shealth fighter also cannot dogfight so what the problem with the F35 also cannot. USAF never keen on dogfighting, they always like to fire off mass AIM-120 missiles beyond the horizon range to knock out enemy aircrafts. each f35 have how many pods for AIM120? even at 2 each per f35, that 24 long range missiles for each f35 squadron. btw, USAF always fight with AWAC support, each AWAC team exercise extensively with it fighters escort, groundpounding f16 and a10. USAF never never fight fair, no mano a mano nonsense in USAF doctrine, it use every dirty trick in the book to go home alive.