WWII German Mk-108 30mm Auto-Cannon Combat Effectiveness Against US Bombers and Fighters 

My grandfather used the Mk.108 in his 109 K4,shooting, the whole little 109 was skaking, but the excellent ammo did the job. He said, what you hit went down,no matter how supposed to be sturdy. His best was 4 P47 in March 45 near Leipzig, chasing civilians...

You're providing WW2 history technical nerds with a product no one else seems to be doing. Great work!

Excellent video 👌🏻👍🏻 The chart with the incredibly low numbers of planes damaged by 30mm projectiles is a textbook example of survivors bias - what these low numbers actually mean is that it was next to impossible to return home if you'd been hit by one of these bullets...

At least someone who does not uses the word "Nazi" five times in every sentence and gives a neutral comment about materiel and events. Bravo !

Superb well-organized video that illustrates how lethal the Mk-108 really was. I was really impressed with the British testing against different types of aircraft. Its amazing what one single round could do.

Ive always wanted Ian from forgotten weapons to do a video on those German 30mm cannons

I can’t get enough of listening to a truly smart person speak on personally researched, evidence based, facts. While considering variables and controls.

and in Hollywood films, pilots simply flew on injured after being hit by Me 262 30 mm projectiles

@11:00 the chart clearly shows that if you were hit by a 30mm mine round, you were not coming home. A very well presented, thought out and well researched video. Keep them coming.

Excellent summary. Had no idea the 30mm was such a devastating weapon. The early Hayabusa had a bad habit of sometimes shooting themselves down when the 20mm rounds exploded in the gun when fired.

This got to be the most informative technical review of the air war in Europe on You tube. Excellent content and very well presented. WW2 nerd heaven!

The lack of hyperbole and matter-of-fact approach are very much appreciated.

11:03 is a good example of survivor bias. Given how remarkably low the amount of damage caused by 20mm, 30mm and rocket fire was on returning bombers, it is quite likely that these rounds were significant contributors to the damage sustained by bombers that did not return.

It would be better to write it as MK 108, as the Germans did, because it represents the word Maschinekanone. I would do this to avoid confusion with the British Mk- designation, which was an abbreviation of "Mark" and is the source of a very common mistake made by English speakers when referring to the MK 108.

As usual, excellent content. Thank you for tracking down and sharing these contemporary reports and providing context as well.

That pilot of that spitfire got as close as you could ever get to being the recipient of that cannon round behind the cockpit. Bet that woke him up a little when it went bang. Legend!

This is one of the coolest videos I've seen in a good long while. I want an Mk-108 now. Thank you, sir.

Wow very lethal 😮 I did not expect that the 30mm had almost 5 times exlosive fill.

I vaguely remember Eric Brown the British test pilot in his evaluation of the Me262 saying that because of the low muzzle velocity of the MK 108 and therefore a need to approach relatively close to a bomber before opening fire, coupled with an extraordinarily high closing speed meant that the aircraft was in desperate need of an airbrake (as per F86 Sabre) in order to bring firing and aiming time up from a few seconds.

Thanks for this. I always guessed that a WW2 autocannon fired explosive rounds, but never knew before what the exact effect was. Now I know it :). Also a great example , like you said of Survivor Bias. Almost no bombers that got hit by 30mm, ever returned!

I always like firing these in the flight simulators With all the good thumpers and headphones running a good bass

Great detail on explosive/destructive power of 20mm and 30mm rounds.

I continue to be impressed by your videos and have been spreading the word. Honestly you have surpassed most of the RU-vid makers in quality of info.

Goring was a huge advocate of the "mine shell" concept. But he was only familiar with WWI combat where the best results were obtained by getting very close to the enemy before firing. And indeed many German ace pilots of WWII agreed with this too. What they didn't reckon on was the huge defensive firepower of multiple 50 cals which outranged them.

I’ve never realized how much those old German 30mms resemble Mk19s

great video! impressive to see the scale of the 30mm versus the 20mm and the explosive yield! I had seen pictures of the results of the Spitfire test firing but the Blenheim clip was the icing on the cake haha.

Truly superb overview. Well done. That 30mm Minengeschoss is fricken terrifying. And an Me-262 with 4 Mk108? 😶‍🌫️🤯

High quality content. Facts with context. Not just endless lists of numbers, dates and locations. 👍👍👍👍👍👍👍🤓

Lower muzzle velocity meant lower muzzle energy. Even forgetting the added size and weight, the recoil forces of the higher velocity MK-103 would have adversely affected a smaller aircraft's controlability, limiting their use to larger twin-engined aircraft. And since these larger aircraft faired badly against single-engine fighters, these higher velocity cannon would have been limited mostly to night fighters, which proved to be the case.

99% of aircraft getting hit by a 30mm didn't make it back

As the B-29 was operated against the Mig-15 in Korea with relatively poor results, leading to the bomber being used at night. It would be good to extend the analysis to the 23mm and 37mm canons used on Mig-15, do you have any data on the performance of the B-29 in that conflict? BTW I am not discounting the performance of the Mig-15 against the B-29 as a modern myth, hence why to ask such a well researched and learned source

Mate I am a 52 y.o Aussie, and my Dad was born 1 Jan 1930, so apparently missed out by 1 day for conscription in Wehrmacht in 1945. He was in the Hitler Youth. My Mum's dad was a Hauptmann in the Wehrmacht as he could speak Russian. He served on the Eastern Front. My Mom's family had to flee their home in East Prussia, as the Russkis were advancing. My uncle on Dad's side was a bomber crewman on Eastern Front. Mum is 92 now, and Dad was 86 when he died. He told me many stories about the war.

The size comparison between the 20mm and 30mm rounds is quite remarkable, while I do not have an actual 3cm Mk 108 round, I do have a couple of the 3cm Mk 101/103 mine rounds (plus one casing) on belt links, the sheer scale of these things would be terrifying to be shot at.

The ME262 had 4 of the M108 in its nose. That solved the problem of the low fire rate. 4 of them fired around 40 projectiles per second!

those demonstration vid clips are rare...and terrifying...never seen anything like that

There was, however, one big problem with the MK 108: it had a very low rate of fire. Something Mauser was trying to solve with the MK 213 revolver cannon when the war ended. Interestingly, the revolver cannon design became the basis for several postwar cannon designs, and Mauser developed it into the BK-27 cannon used on several modern fighter designs.

Nice video, thanks. Speaking of Japanese 20mm cannons, I remember an interview of a Japanese pilot where they asked him how he felt about their 20mm cannon - He said it had "a trajectory like a stream of piss".

9:08 _"...the detonation reduced the wing structural integrity and aerodynamic performance..."_ *shows obliterated wing...* ...Welp, here we got the understatement of the year, presented in rarely heard engineering terms and with amazing documentation! Annnd leaving this silly joke aside, sir, you won the internet today. The research, the perfect edition and scripting, you gave a University-level lecture on the subject. I tip my hat to thee, fine gent. +1, Subbed obviously, absolutely fantastic job, thank you, very much!

11:00 this table has some other interesting data, like how ''self inflicted damage' goes down over time, and 'empty shell cases and links' can be dangerous.

Excellent vid dude.... greetings from Lima-Perú!!!

The Mk-103 was the "long barrelled" version basically. It had high muzzle velocity but it was less destructive and weighed a lot more. I recall choosing the 103 a lot in the old air combat sim SWOTL from the 90's. I guess I wanted to hit more accurately, I don't remember exactly. : )

Coincidently just started watching Masters of the Air series. This video really gives me some information to think about while viewing the series.

It should be noted that no K-6's really were used. The K-4 had access to a single 108, or with addon-gunpods could fit 3 of them.

Good video, I enjoyed the depth of research, digest, analysis and explanation (as opposed to copy pasta from the interwebs). But did you say at 7:19 that one of the disadvantages of the MK 108 was a low rate of fire? That cannon started out at 660rpm during pre-production, and later went up to 850rpm - which was higher than the rate of fire of the AN/M2 50 cal then in service. In fact, unless I'm mistaken, it had the highest rate of fire among aircraft _cannons_ in WW2. So at the receiving end of an Me 262's battery it'd literally be raining HE... Edit: Also, the MG151 was a 15mm cannon. It was later upgraded by necking out the 15mm round to 20mm, which was easy to do and required little other modification - largely, just the barrel. The cannon then became the MG151/20 - _that_ is the 20mm cannon you're referring to.

I think most people don't realize how much more dectructive the 30mm grenade was because the numbers, without thinking about it, don't intuitively sound that bigger > 20mm vs 30mm. But as shown the 30mm packs about 4.7 times as much explosives as a 20mm shell. The ground test footage shows really well just how effective even a single shell was. It is no wonder the English and French switched to a 30mm (ADEN/DEFA) cannon in some planes after WW2 (Hawker Hunter, Mirages). I guess the Russians also drew the same conclusion when going to their 23mm, 37mm and larger guns.

You really are presenting valuable information that few, if any, other platforms are providing. Nicely done!

10:50 : About survivor bias, I'd suggest reading the Wikipedia article on Abraham Wald, a member of the Statistical Research Group at Columbia University during WW2. In particular, check the 2nd reference by Marc Mangel and Francisco J. Samaniego, Wald's Work on Aircraft Survivability of June 1984. It explains how Wald estimated the various conditional probabilities (for a hypothetical dataset in the article) about the survival of aircraft, using only the data observed on returning aircraft. If someone is skilled enough, he may apply Wald's method to the Eighth Air Force data. Note we'd probably need finer data such as the number of hits sustained for each aircraft, which type of ammunition hit, and the hit location as well.

Your videos are gems great work. Just watched gun camera videos from over Germany, cant believe the B17s were taking hit after hit after hit still flying absolutely insane

Thanks for video. I knew that these 30mm rounds were very destructive but I did not know they could pack more punch than a hand grenade!

Reminds me of the MK19. I wonder if they ever configured it for a ground role.

One hit with a Mk108 would destroy a fighter or bomber.

One thing that made a great deal of difference was the mounting of 'schrāge musik'. Night fighters approached from underneath the bomber, in the blind spot and used upward firing guns directly into the fuel tanks.

Great work. Thank you for the time you put in here.

In one word: "excellent", on a theme long overlooked. Makes me wonder about how modern 30 mm peformance like that of DEFA/Aden guns in more recent conflicts would compare.

I was waiting for a comparison to the mark 103 auto-cannon. The Mark 108 did have the low muzzle velocity of 1,770 ft/s. But the mark 103 auto-cannon had 3,100 ft/s !!! really a different beast.

Very well researched, I always get annoyed at RU-vidrs wiki videos but you actually read up and even had some stuff I didn’t know and I’m a real wwii geek.

Regarding the Me262 people always forget to add the speed difference to the aircrafts it attacked to the muzzle velocity og the MK108 cannon. If a Me262 attacks a B17 from the rear you need to add more than 100ms to the nominal muzzle velocity of the 30mm Mk108 cannon. Attacking from 90 degrees the actual velocity of the 30mm shells are 200ms+ higher than the nominal muzzle velocity. The grenade trajectories are completely different from what people imagine they are. The Mk108 shoot flatter from a Me262 in attack mode than from prop driven fighters due to the difference in actual velocity of the 30mm shells.

It would be interesting to lean how the cost of these various rounds compared. These 30mm cannon rounds sure could do a lot of damage but how much did they cost to produce? Thanks for another really interesting video.

Why is the barrel on the MK108 so short? I would think having a longer barrel would increase muzzle velocity resulting in better accuracy and longer effective range.

Very informative! That 30 mm had 1.5 x the explosive charge of a WW II "pineapple" grenade. Now THAT'S deadly.

Your dedication to complete information and facts means that your website is of great importance to historians. There is so much unresearched 'romanticised' rubbish on RU-vid - and no 'music' - thanks. The chart showing flak to be the greatest threat is consistent with my own findings but there is no 'romance' in flak.

The number of bombers damaged by empty casings and links is actually kind of shocking 10:30

More explosive filler than a regular grenade omg. This thing was basically a self-propelled mini-flak gun. Thank you for this video! It's the only one I could find about this!

Outstanding technical details with clarity of context. I appreciate the reality so much better. Question, how did USAF fighters manage to shoot down anything with only 6 to 8 50 caliber machine guns, firing non explosive rounds? It is sobering to realize 3 to 5 rounds of 39 mm downed big american bombers. Was a P 47 with 8 guns and 3,400 rounds requiring 1,600 rounds to kill an enemy fighter? I realize the 30 mm round was much heavier and bulkier. But IF a plane carried 3,400 of 30 mm cannon shells there was enough lethality to down 1,133 four engine allied bombers. There were only 12,000 B 17s manufactured. I know, the limiting factors but OMG. I read an account in the offucial war diaries of the 34th division of the Iowa National Guard in combat in Europe. It details seeing a flight of 12 B-17's unescorted flying over tjeir unit. It took 2 minutes for 8 german fighters to shoot them all down, filling the sky with parachutes. Ground troops werevshocked at how quickly and effectively it happened. Late stage of the war, gauging how that went, likely experienced German pilots. Adolph Galland commented how easy and pleasureable it was later with the heavier armament he eas supplied with to rip apart, take wings off, gouge open fusealages, American 4 engine bombwrs in a single pass. He said it with real relish, saying how powerful it made him feel. The brits lost 57,000 killed. The americans, 71%. That's correct, 71%. Mostly killed. 100,000. Relatively overlooked 15,000 amwrican aircrew were killed in training before seeing combat. The strategic bombing campaign destroyed 2 large Tiger tank production facilities, beyond repair, BEFORE thet made a sungle tank. Damaged oil production and fuel refinement, diverted 80% of german fughters to the West, and 80 of the dreaded 88mm flak guns, dual purpose anti tank weapons to thw West, away from the Eastern Front. So when the Russians whine about they got to do most of the dying, with 29,000,000 casualties, they are not without cause, but they aren't telling the whole truth.

Excellent technical video of the effectiveness of the MK108 auto- cannon! Thank you for your excellent presentation!

Very well made, informative and unbiased video! Thank you very much.

30 mm Aden gun pods (made in UK) were used after the war on many aircraft. It was derived from the German design. I helped attach and remove 30 km gun pods from A model US Marine Corps Harriers. As a part if a maintenance team.

In 1939 the standard PAK had 37mm armour piercing grenades. Just for comparison. These mines are different but nearly the same size.

Absolutely amazing series of reports. Although crammed with technical info, the videos flow & make for truly enjoyable & informative viewing. 👍

Really enjoyed learning about these, thanks for making the video.

Great information and well represented. One criticism if I may.... mk108 is correctly termed Mark 108. This was the common usage of this abbreviation but hasn't seemed to have trickled down to the younger generation. It is often mispronounced especially when presentations are auto generated. Great job! and keep it up.

This engineer really enjoyed this. Well done!

PLEASE KEEP THE MESSAGE AND MISSION COMING......!!!!!! THESE VIDEOS ARE A MUST WATCH VIDEO.....TWICE..........!!!!!! NO ONE IS POSTING THIS INCREDIBLE INFORMATION......!!!!!! All of these Technical Specifications are not available elsewhere. You are a Compliment to this Profession. Thank you for your VIDEOS Sir.

Soviet fighters also used heavy caliber auto cannons, and so did ground attack aircraft such as the feared IL-2 Sturmavec which had four 30mm cannons. The Soviet fighters after WW-2 had 23mm, 37mm or both caliber cannons.

Nice video. I always assumed 30mm being 1/3rd larger, would do about 33% to 50% more, at most double the damage, compared to 20mm. I was way off.

Brits made some cool videos, it was very nice to see it "in person" how devastating that cannon was. That spitfire/hurricane wing and tail got annihilated, and same to be said about bomber. I wonder if they made same test for Mk103 that had much higher muzzle velocity while having comparable shells.

Excellent video, thank you! I really enjoy watching your content.

1:34 fascinating chart. That chart tells the whole story of the air war.

A degree level lecture on aircraft weaponry. Excellent.

Great video! Lots of good info. I like the graphics you added 👍. Those cannons were crazy! Insane they put them on planes.

“Muzzle speed” that’s the first time I’ve heard that one. Usually it’s always “muzzle velocity”.

Unexpected, but true. While in the US Marine Corps, I was assigned for awhile to VMA 513, that Harrier Squadron had 30 mm Aden cannon. We were stationed at Cherry Point at one time. A not too bright ordnance junior enlisted, brought a shell to his room. While attempting to remove the powder from the shell , so that he could take it home as a souvenir, it went off. He blew his thumb off. And the 30mm projectile went though all the rooms walls and outside. My own room had a hole in both walls. Thankfully, I was out working when it happened.

Well, you said it yourself: Returning Bomber Statistics might be very misleading - only very few Bombers returning with rocket- or 30mm (fragment) hits could also be well interpreted as them being far more lethal to the bombers, so only a few returned with damage, while most hits were fatal and resulted in total loss. In return this would also mean, that the 20mm was not so effective, as a lot of bombers were damaged, but not taken out in the theater.

A very good presentation. Precise and informative. Thank you for this film.

Good video but I think you missed something: the Germans had developed a base-fused 30mm round which enabled a thinner shell casing and hence greater explosive fill. I recall that it was used operationally so this would skew the damage statistics.

really enjoyed all the technical information ans pictures of damage caused. Thank you.

I always thought the mk108 was the first automatic grenade launcher, after watching this video, I wasn't wrong

In an interview on the history channel, a ww2 fighter pilot said one hit from that nose mounted 30mm would rip your mustang in half.

Dude...that a hellof a video!!! Thanks for sharing and all the time it took to make.

A US bomber crewman whose plane was shot down by a 262 using 30mm cannon said that it was possible to drive a truck through the hole made in the plane, though whether it was the result of one hit or several was not clear. In any case he bailed out and was captured - not all his crew made it.

The MK-103 was much deadlier as it could spit out the same shells with high velocity. It was a lot heavier and more expensive to produce however

The content of your video is always excellent and the subjects you highlight are always interesting.

I would say the most important quality of the Mk 108 is that it was pretty lightweight, at 58 kg. This is twice the weight of a .50 calibre AN/M2 or roughly 1.5 times the weight of your average 20 mm cannon. However, its relative efficiency against bombers was much higher. The best all-around aircraft weapon of WW2 was probably the 20 mm cannon (I would say the Hispano-Suiza, due to its light weight and high muzzle velocity), but for an anti-bomber weapon, it was definitely the Mk 108.

The undoubted advantage of the 30mm cannon was the firepower of a single bullet. On the other hand, the undoubted disadvantages of this system, were the low range, accuracy and velocity of the projectiles.

Im suprise how short is the canon, I was expecting something longer like Hispano.

Well the last shart only shows greater survivability from the 20mm versus the 30mm then? Hmm… few pictures of bombers returning with damage from the 30mm…

Interesting that the U.S. mostly only upgraded to 12.7mm after the .30Cal. They did have armor-piercing and incendiary rounds though. Would like to see a statistical comparison.

I’m not sure how true it is but story goes that B-17 took a 30MM hit in the cockpit and blew apart the co-pilot, destroyed many of instrumental readings but the pilot held his sanity long enough to get home; When he landed, ground crew had to pry his hands off the yoke, poor guy was shell shocked. Lot of bombers did survive taking hits by those tator rounds but fighters on the hand rarely did. I’ve only seen it once years ago but there is gun cam of a P-51 taking direct hit by I believe was a 30, literally blowing it up quite similar to footage of the 190. Pilot never had a chance.

Very good analysis! I always wonder the effectiveness of cannon, now I understand. Thanks!

The nerdy voice of the narrator ADDS to the authenticity of the information presented!