Watch an F-35A fire 181 rounds from its four-barrel 25mm Gatling gun embedded in the left wing

F-35 fired its embedded gun at full capacity.

The F-35 Integrated Test Force has just released an interesting video showing the 181 round gun burst of the 25 millimeter Gatling gun embedded in the F-35A’s left wing root.

The video was filmed during a ground test at Edwards Air Force Base, Calif., Gun Harmonizing Range on Aug. 14; initial shots were fired on Jun. 9 and ground testing should be completed by the end of this month. Airborne testing is to start in the fall and at the end of the firing campaign the gun will be operative by 2017.

According to LM, the F-35 flight sciences aircraft, AF-2, underwent instrumentation modifications and used a production version of the GAU-22/A gun to achieve the full capacity of 181 rounds: along with practice PGU-23/U target practice rounds (which do not explode on impact) software to replicate being in flight was uploaded to the aircraft to conduct the test.

The F-35 GAU-22/A gun has been among the most controversial topics lately: some criticised the fact that the Joint Strike Fighter’s gun can only hold 181 25mm rounds, fewer than the A-10 Thunderbolt’s GAU-8/A Avenger, that can hold some 1,174 30mm rounds.

Interestingly, the gun is hidden behind closed doors, to reduce the plane’s RCS (radar cross section) and keep it stealth, until the trigger is engaged.

While the F-35A will be equipped with an embedded GAU-22 gun, the B (STOVL – Short Take Off Vertical Landing) and C (CV – Carrier Variant) variants will carry it inside an external pod capable to hold 220 rounds.

Image credit: F-35 Integrated Test Force


About David Cenciotti
David Cenciotti is a journalist based in Rome, Italy. He is the Founder and Editor of “The Aviationist”, one of the world’s most famous and read military aviation blogs. Since 1996, he has written for major worldwide magazines, including Air Forces Monthly, Combat Aircraft, and many others, covering aviation, defense, war, industry, intelligence, crime and cyberwar. He has reported from the U.S., Europe, Australia and Syria, and flown several combat planes with different air forces. He is a former 2nd Lt. of the Italian Air Force, a private pilot and a graduate in Computer Engineering. He has written five books and contributed to many more ones.


  1. 181 rounds? all that weight and design cost for 181 rounds…i hope it shoots magic bullets.

    • I guess it’s because it doesn’t take that many bullets to at least disable a plane. Just a few hits should do :)

      Another argument against it could be that the F-35 is supposed to fight BVR. I recall a US official telling that the F-35 would be at a disadvantage WVR, and that if it came to a close range combat, the pilot (and associated intelligence) didn’t do their job properly. I can’t remember whether he was related to the air force or navy though. Anyway, if the F-35 isn’t supposed to do battle WVR, then surely a gun wouldn’t be necessary either?

      • I think F-4 wasn’t build for dogfight too, since they thought it can win a battle in BVR. A few years later, they made F-4E…

      • When they say, “didn’t do their job properly” they’re saying is that they should have been maximizing their advantages. Same with the F-22. Same with the F-16 if the pilot lets a Hornet or Fulcrum pilot suck them into a low speed dogfight. You fight with your strengths. That goes for every aircraft. For example, (all else being equal) the F-16 will generally beat the Hornet in a dogfight if the F-16 can force the Hornet to try to keep it’s speed up. The Hornet will generally win if he can get the F-16 to try to fight at a slower speed. Which one sucks? Neither. Put in another context, soldiers generally carry rifles and knives, but if they find themselves going hand-to-hand with knives somebody f–ked up somewhere.

      • When the F-4 was designed, everyone was convinced that dogfighting was obsolete. The plane didn’t carry a cannon. In combat in Vietnam, they quickly learned that the air-to-air missiles seldom hit their targets (<10%). They also learned that if you got in too close, you were inside the minimum range of the Sidewinder missile. They quickly added gun pods to the Phantom and later added an internal cannon. Missiles have both minimum and maximum ranges. For long range shots, there's the AIM-120. For closer in shots, there's the AIM-9X. In case things get in too close for a Sidewinder, there's the cannon. Once in a while, the Air Force might use the cannon for ground support. When ground troops are in a "danger close" situation, you don't want to be dropping bombs that could just as easily kill your own people.

    • How many rounds does the Gripen, Typhoon, Rafale, Flanker (any flavor), Fulcrum (same), have? Exactly. The F-111 could carry a tank of 2000+ rounds in it’s internal bay. Maybe you should be complaining about what piece of crap the A-10 is because it only carries half that much. Right? Right?

      • sferrin, I know you were a project lead on the F-35 team, but people are entitled to their opinions, even if it goes against your design. Not to worry, the A-10 thunderbolt II will be out in 2017. They are working on that in the cube next to yours.

      • sferrin, calm down buddy. What guest is referring to is that the F-35 will never work as good as an A-10 in the close air support role as the A-10. As a matter of fact, one of the reasons the Air Force supposedly want to retire the A-10, is that they will use the F-35 in such a role. But one doesn´t need a PhD to figure out that with only 180 rounds, you are not going to be delivering much lead to the ground. And if that thing still want´s to remain stealthy, they won´t be carrying anything on the stubs, thereby greatly minimizing, the weapons load as well. In the close air support role, there is no equal to the Warthog.

        • People who claim that the F-35 will never be as good at CAS as the A-10 have a very poor understanding of how the CAS role has evolved in recent years. So lets clear up the first thing: the vast majority of the CAS provided by A-10’s is not done with the gun. 95% of the time they’re using precision guided bombs and air-to-ground missiles. The A-10’s gun and strafing runs in general are danger close and collateral damage nightmares compared to the PGMs in use today.

          Second, the A-10 is too slow to respond TICs in a timely fashion. For this reason, F-15Es, F-16s, and B-1s have actually be pulling the majority of the weight in Afghanistan regarding close air support. A-10’s are only doing about 20% of the CAS despite it being basically their only job.

          Finally, your argument that the F-35 won’t be able to carry much if stealth is required for the mission is true, but ultimately a moot point. If stealth is required, A-10’s wouldn’t be going in in the first place. So how exactly does that make the F-35 inferior? The A-10 is a great CAS platform IF you already have air superiority and don’t have to worry about advanced surface threats. But the F-35 will be able to show up to the fight much faster, avoid far more advanced threats on the way there, and aside from the gun (which is barely used anymore) will be able to deliver all the same munitions that the A-10 can.

          • This. I wish the A-10 fanboys would get off their armchairs and actually talk to a recent Vet about CAS just once.

            • I am an A-10 “fanboy” but I respect what the possibilities of the F-35 bring to any battlefield simply because it will go where the warthog can’t or quickly enough “speed is life”. But the fanboys will always rally around the fact that A-10 carries more by the ton and is armoured, this allows other possibilities. There is also the loiter time that allows A-10s to “hang around” for damage assessment or simply to hawk over a hiding target or for “search and rescue operations” where they need to go low & slow. CAS may be the majority of current A-10 missions but it is not the only one it is capable of doing. Statistics hurt us if we concentrate on them too much.

              While the Fighters are frontline widow makers they don’t always have the endurance to continue providing support in the form of fuel efficiency, ammo supply and logistical maintenance. I hope this changes because the A-10 is a CAS oriented design from the 70’s co-worked on by a Luftwaffe Stuka pilot from the 40s… There has got to be something to fill in this ground support niche, maybe the Scorpion but it doesn’t “look” to have the same armour and redundancy which allow/afford the A-10 to risk CAS missions in the first place.

              • Armor, oh so important when the threat was 23 mm cannon fire, is simply not relevant anymore on a battlefield where even ISIS is carrying SA-7s. I have a ton of respect for what the A-10 did in the past, but it simply will not survive modern operations.

                • Well armor on a plane is a novelty unto itself so I’m not expecting it to simply shrug off missile warheads, it will have to be thicker for anything BUK-like or vehicle/platform mounted but it will have far better chances of surviving a manpad. In war there is no 100% this or 0% that, but the difference in survivability is significant, not to mention pilot survivability, theres no ignoring that. While we talk about modern warfare, stuff like cannons and ground flak will exist for a long time due to its availability, low cost, standard communist ammo and, well, its everywhere and will be battlefield staple until the days when the AK-47 is replaced which will be a long time even after it becomes “obsolete”.

                  Also the sa-7 and idea of manpads was already coming onto the war theater as the A-10 and Russian Frogfoot were still on the drawing board so me thinks that the armor was also intended for those eventual hits made by manpad. A 1.15kg warhead means a world of a difference to an aluminum target compared to something “armored” with multiple redundancies. Then again with modern metallurgy entering the 21st century, the F-22 with its Titanium body could also be considered “armored” but thats mostly just the frame, the A-10 and Frogfoot were designed to be redundant and have the extra plating around pilot, airframe, engines, etc but I’ve seen enough footage from the Russian-Georgia war to see Frogfoots being shot at low level at people assumed to be manpads, good footage, hope you can find some.

                  Again, there is no certainty in war but Murphy, armor only helps swing the favor of survivability and endurance to carry out the mission closer to the pilot.

                • I made a similar comment to an A-10 fan comment on this site before. I grew up watching A-10’s fly all the time in Pennsylvania. I have a great respect for this aircraft. But the US has showed time and time again that it pays to be looking ahead, and even in the face of countless design challenges, it pays off to be a step ahead of the competition. I am concerned for any A-10 pilot flying low and slow over ISIS controlled territory. These clowns have money and advanced arms to knock down all sorts of different aerial targets of opportunity.

      • You make some good points, sferrin, but which weapons systems are used in deadly close situations? The big ass gun. This happens quite a bit in urban warfare. Bombs, rockets, even precise missiles all are useless when trying to avoid collateral damage. One, maybe 2 passes by the F-35 while the A-10 has many. Bid ass bullets will defeat an entrenched enemy many more times than explosive weaponry in these danger close situations. I have zero problem with the F-35 for use in the future but in today’s conflicts, the A-10 is just more useful than the F35 would be in CAS. F-35s can initiate contact until the A-10s arrive if they weren’t already loitering in the area. After the A-10s take over in CAS, the F-35s could provide CAP for the duration.

        As for the F-111, the A-10 carries 1100+ rounds of 3 types of 30mm for any mission. Oh, and it’s very low speed is also a big advantage over any fast movers.

        Really good point on stealth, although, we won’t need stealth as much after the initial attacks by the F-35, F-22, and B-2. This is when the Warthog would shine with the F-35 and /or F-22 as air cover.

  2. Unfortunately, the fat F-35 is too heavy & slow, with a turn rate like that of a B-52, to get a lock-on with its guns.

    • The F-35 has a 9g turn compared to 3gs for the BUFF. And once all the software upgrades are completed it will have an AOA of greater than 50degrees!
      The 25mm gun is larger than the F-15 and F-16 that support CAS now when A-10s are not available and I don’t see anyone bitching about how ineffective they are. I love all these armchair pilots who don’t know a damn thing about what this aircraft can really do! Once it becomes fully operational all the whiners will stop complaining and say they were supporters all along!

  3. There are some jobs that simply don’t require a high tech design to do. The F-35 will never be an F/A-35, so why are they wasting money on this crap? No one in their right mind is ever going to roll that aircraft down in the dirt over a ground target. Upgrade the A-10 at a fraction of the cost and improve off of that platform.

    • Well I’m hoping for a A-10D or something to upgrade the warthog, its not a platform thats going to disappear overnight or any time before the decade is over with.

      A-10C was supposed to get modern electronics so wouldn’t newer ECM pods, better armour materials and a brand spanking new sensor suit make it a cost efficient project? Of course, the F-35 has been getting its budget by stealing from other platforms budgets… so maybe we should ask a white collar peanut counter. (no disrespect to white collar workers or people that actually count peanuts for a living)

  4. So that is what is replacing the avenger cannon? I think they should call this the FU-35 :'(

  5. Ground attack and cover just as well as the A-10? Maybe for about 2 or 3 seconds then off to get more bullets while our people die on the ground. That’s not even including the psychological effect on the enemy while the Warthog is loitering for an hour just looking for targets. Damn, even the military is greedy with its need for expensive less capable toys.

    • Most A-10 ground kills in the last 25 yrs have been with the AGM-65 standoff weapon, which the F-35 can carry. The gun is spectacular, but not really that important. Not even the A-10 is being flown like the A-10 anymore. :-D

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