The Ugly Truth: Cannons better than .50cal?

hey everyone it's chris from military aviation history and today i have a question for you 50 cals or 20 millimeter cannons during world war ii the us had a very special relationship with the 50 cal m2 browning and u.s armed forces continued to use the weapon even today if there is a weapon that stood the test of time it is the 50 cal m2 browning in its aviation variant this weapon was used as both an offensive weapon on fighters like the p-51 mustang and as a defensive weapon on bombers like this b-17 flying fortress both aircraft that you see here were filmed at the raf museum in london introduced in the 1920s it started to be used on aircraft by the united states army air corps which later on became the army air force and they used it on basically every plane at that point as did the united states navy and the marine corps and overall the weapon really did rather well there is of course the exception of some outliers like the p-38 lightning that also used a 20 millimeter hispano cannon but even that plane had four heavy machine guns under the hood and overall the 50 cal was the dominating aerial gun for us aircraft in world war ii and just to be clear 50 cal of course translates into 12.7 millimeters in metric on the other hand by and large german luftwaffe aircraft featured a split armament of initially light and then heavy machine guns from the mg-17 and then the mg131 firing a 7.92 millimeter and then a 30 millimeter round respectively mixed in with one or two or even more 20 millimeter cannons depending on the plane type and variant of course i'm only talking about the fighters here because the armament was slightly different on the bombers but we're focusing on fighters first the 20 millimeter cannon was the mgf based on an oerlikon design then it became the mg151-20 which was a different gun by mauser and of course then also the luftwaffe switched to the 30 millimeter cannons but i will come back to that later on now every now and then i see this question pop up you know people asking what was better 50 cal or 20 mils and there seemed to be a lot of different takes on this so today i want to weigh in on this topic let me make one thing clear from the start i will not be saying that any of these weapons is better than the other because first of all i do not believe that this is possible it's an apples and orange situation and quite frankly i find it somewhat reductive and often more based on cherry picking rather than looking at the context both the us and germany found itself in during world war ii which did influence their respective decisions to go with the 50 car or with a heavy air cannon armament now you might disagree on that but hear me out first and then i'm be more than happy to take a look at what your takes are down in the comments section both of these choices in my opinion the 50 cals in the hands of american pilots and aviators and the cannons in the hands of the germans make perfect sense for both of them given their operational and tactical context that they will use them now there have been both back in the day and also now been attempts to compare these guns based on various properties right for example power to weight ratio to know how much bang you're getting for your buck or burst mass to know how much lead you're firing off in let's say a one second burst or any sort of over hard data analysis and that is one way of doing these comparisons and i'll be drawing on some of that data here as well in fact there was a very good website and book that i'm drawing some information from and this is was written by anthony williams and dr emmanuel gustav they have multiple books on weapons and compare them as well sometimes based on calculated data but also with some extra context and i'll draw on some of the data later on but i won't be doing a mathematical comparison outright except where i think that it is required because first of all you can read it on in their book and on their website and also because i think that for the purposes of this video looking at the context of use rather than the hard stats it's a more organic way of explaining the topic of why these weapons were used and not about how they stack up against each other let's look at the u.s first when world war ii started in europe in 1939 the u.s was not yet involved and it would not be involved for another two years say you know pearl harbor that was in december 1941. during this time and before this already it was using two different weapons on their planes mainly two different weapons one was the 30 cal that's 7.62 millimeters in metric m2an based on the m1919 browning later on improved via the m1921 and further models as well the other gun was the 50 cal m2an and yes both guns were known as the m2 while the an stands for army and navy showing that it was used by both services there were also some versions that were only used by the army and only used by the navy but overall they actually standardized around the same gun to keep things simple in this video i will be referring to the two guns by the caliber only the ferdi cow was similar to the light machine guns many countries used at a time overall it of course differed as a gun but the caliber was roughly the same as an aircraft gun it was different to its ground-based cousin however having been lightened but the fertical m2 browning was never an let's say ideal gun for air combat yeah it remained heavier than comparable guns was more difficult to synchronize with the propeller without dropping the fire rate too much and it was also prone to jamming the us had started to introduce the 50 cal however in the 1920s the 50 cow had of course a higher caliber and when it started getting introduced it was one of the heavier guns in aircraft available at the time globally and by that i mean both in caliber and in weight and the 50 cal even in its lightened aircraft version was a heavy gun but we'll see more of that later on as well now when the 50 car was introduced were in the 1920s here around this time even into the 50 caliber bullet was a very heavy bullet for an aircraft for this i need to make a little excursion to talk about aircraft designs we need to remember that before world war ii planes were generally lighter constructs and carried very little protection the first attempts were made in world war one to add armor but even a very small insignificant plate let's say of a width of 30 centimeters that's about a foot and maybe a length of 60 centimeters that's about two feet um would be significantly impairing a plane operating on an engine running on like what 200 slightly more than 200 jeremy clarkson's but to a point one might have assumed what was going to happen because we see this increase in engine power even happening in world war one in the beginning of world war one we're operating on engines that are less than 100 horsepower and later on we are beyond 200 horsepower by the end of the war so you can see that perhaps with increasing capabilities in these engines the aircraft will also be able to carry more weight and that is correct to a point except that on fighters nothing really changes in terms of protection for about 20 years had world war one continued maybe we would have seen a shift to armor and protection sooner but it didn't the shift to the monoplane however and an all-metal construction was a very recent one in the 1930s it happened sort of in the mid 1930s and it was not yet finished when world war 1 started in 1939 many planes for a long time had been constructed via a wooden skeleton especially in world war one or a metal two builder construction now i'm showing a few world war one aircraft here so you can really see what i'm getting at this aircraft here has that wooden skeleton that i talked about and it's only covered in fabric here is a german albatross as a comparison it doesn't have that fabric covering but instead very thin wooden sheets to cover the fuselage and then there were some aircraft in world war one that also had a metal tubular construction a little bit similar to that wooden skeleton that you saw earlier and the aircraft like that had this included the iron decker of course which is quite a famous aircraft and then of course also the fokker d7 which you see here i also have an inside the cockpit video on this aircraft and the albatross where i talk about them in more detail so consider looking at those videos as well after this one other aircraft in world war one like the german roland for example were also already experimenting with light metal covers on the fuselage but those cases were outliers during the interval period the shift to metal coverings becomes more common there have been improvements to construction and design but it is still largely based on the same principles that we see in world war one even the hawker hurricane in fact of world war ii had a composite construction of a metal covered front section and a fabric covered aft fuselage in fact the first wings on this aircraft were also fabric covered but that quickly changed to metal-covered wings anyway so in the 20 years following world war one a lot of things changed but a lot of things stayed the same as well but it was only with this significant increase in engine performance in the late 1930s that really heavier firepower and also protection became an option for these aircraft and we're really talking about the introduction of some of those really famous engines that you hear about in world war ii yeah the daimler-benz 601 of course the rolls-royce merlin as being another example still by the time of the spanish civil war so we're talking the late 1930s here we are seeing that bombers for example are often still faster and outperform fighters or that even if the fighters are able to outperform bombers they lack the firepower to shoot those aircraft down because they are mainly limited to machine guns the increase in firepower and the increase in protection and the increase in performance in fighter planes happens in a very very short period of time really in the late sort of the mid to late 1930s and it really isn't complete until the very beginning of the 1940s anyway going back to the spanish civil war this is not long before world war ii as i said the spanish civil war only ended in 1938 yeah a year before this the phrase the bomber will always get through was actually somewhat valid and of course there are new fighter models that get introduced in this time yeah the soviet uh polycarp of i-16 perfect example uh the british hawker hurricane super marine spitfire another example the german messerschmitt bf109 again those are aircraft here where you are seeing them starting to outperform bombers in terms of speed and performance and they would also soon be able to carry the amount of guns they need to be a threat to these bombers but that really happens around this period of time in the spanish civil war really at the end of the spanish civil war but before that bombers and these larger aircraft that really don't look that fast were actually a lot faster than the fighters which were mainly still bi-planes now even as fighter performance increases and firepower increases in all of these aircraft fighters by and large with very few exceptions had no armor during this time the late 1930s and even the beginning of 1940s armor really only starts to gain traction on fighters yeah in just about 1940 during the battle of britain you might say there are some cases where this already happened earlier but overall it's 1940s in the battle of britain especially with german aircraft and british aircraft this is when that happens but to go back to the us here armor on fighter aircraft was actually even relatively rare or hasn't been really been standardized yet by the time of the battle of midway which is which was in june 1942. of course army planes for example like the p-49 did have armor in fact it had it had a bit too much armor that one and that's one of the reasons why this plane was very limited in operational terms in the south pacific at this point in time something i will have a video on very shortly in fact if you're a patreon or channel member you probably already have access to it other planes like the p40 also had some armor but for the us navy for example the f4f wildcat only got armor sent by the industry later on and carrier crews around this time initially improvised by adding some root of armor protection themselves for their pilots even by early and mid-1942 for a lot of pilots it also has to be said it doesn't matter if they were american if they were european soviet japanese italian doesn't matter armor was disliked in the beginning yeah it it was felt that this made a plane more sluggish and unresponsive and there is some truth to that a proper armor plate let's say of a certain thickness usually this was between in world war ii this was between so at the low end six millimeters usually about eight millimeters which is i believe a quarter to a third of an inch to about 10 to 12 to 13 millimeters at the high end at this point we're about half an inch um it it was heavy yes that stuff could weigh about you know 100 kilograms easily about 200 pounds essentially the equivalent of a small bomb that were also carried around this time pilots considered agility and speed to be their primary defense and that's not exactly wrong but more and more pilots especially during the battle of britain we see this being introduced very slowly first with sort of armored windscreens then with an up protective headrest not covering the body yet and then that full body plate behind the pilot seat covering the body and that really is a process that sort of starts in may 1940 especially for the british and the germans are slightly slower than that they start rolling out the first protective measures in june um but it really takes 1940 to complete set of 1940 for that really to be becoming standardized but after that it really is standardized and armor really gains traction it is considered a thing that is necessary to protect the aircraft actually not to protect the aircraft on fighter planes armor is only meant to protect the pilot not the machine and i always like to borrow a term from tabletop games here armor should not be considered as a means to guarantee protection we should really consider this more as a saving flow yeah everything has gone wrong and the pilot either has not noticed his enemy or was unable to shake him and he gets another chance to live because of the armor his machine however his aircraft will probably get damaged or even shot down nowadays with a lot of hindsight of course we often criticize the asic m0 that main japanese navy fighter aircraft japan had of course two air forces the army air service which had completely different aircraft to the naval air service or not every japanese fighter was an a6m0 of course but we often consider that aircraft to have yeah and have no protection when it comes out in 1940 and that is true the a6m0 does not have any protection measures when it comes out in 1940 but we also forget that this was nothing special at the time what was special with the xero is that for a long time it did not receive protective measures as this became a standard thing in other aircraft including other japanese aircraft also there are good reasons why the xero never got any protection until the very end but that is something for another video anyway to continue the explanation of what's going on around this time on bombers and on heavy aircraft this was somewhat different to fighters bombers had the performance to actually be able to carry weight and agility wasn't that important and a few extra pounds of armor could be compensated for to a degree usually there was already also some rudimentary protection built into the design simply by virtue of being a bigger plane you know bullets had to pass through a larger space they would be hitting multiple frames or multiple pieces of equipment and thus they wouldn't cause that much damage to some of those critical areas sometimes you even have already had an armored bulkhead or some very early fuel tank protection but that was even rarer in the late 1930s as the war progressed next to the crew sometimes engines also got armor the british lancaster avril lancaster coming out in 1941 had very small armored plates to protect the engines as did the earlier hanley page halifax for example but this was also more done due to the experience case in the first years of world war ii rather than being there by design mind you the b-17 for example focused entirely nearly entirely on protecting the crew rather than the engines so this is the engine protection was one thing that the british did alongside crew protection for fuel tank protection in the first years of world war ii this was still an entirely new thing for example there is a german bf-110 that fell into british hands pretty early on i believe it was in norway but this is something you can also read up in richard dunn's book exploding fuel tanks really good ebook as well definitely recommended the british found a protected fuel tank a very early type of protective fuel tank in this aircraft it wasn't as good as later models but they were very interested in it and they also shared it with the us so everybody tried to work on this a little bit but again only when the fighting started did it really gain traction and a lot of existing models around this time especially if there were fighters like the super marine spitfire or the messenger 109 had problems installing something like a protected fuel tank because the initial design didn't anticipate this also a protected fuel tank depending on the tank decreases the amount of fuel airplane can actually carry because the volume gets decreased by the fuel tank which doesn't change in size yeah it often cannot change in size because of the spatial limits inside an aircraft and thus you have to take a space away from the actual fuel reserve to install those protective layers and not only does it increase weight then yeah it also decreases the fuel amount of the plane carriers and that results in less range which is also one of the answers to why this zero never got it anyway to bring this to a close i know i've been a little bit of a tangent but this is very important context aircraft in the 1930s were of lighter construction had less protection and usually carried fewer guns the eight guns on the hawker hurricane and the supermarine spitfires are a complete outlier the usual number of guns had only just increased from two light machine guns which had been the standard since world war one for the next yeah well nearly 20 years to something like four machine guns this is only happening now with the spanish civil war and really just 1938 and most most planes and a lot of action and actually a lot of planes even around this time still operate around the premise of two or four light machine guns and sometimes two heavy machine guns depending on the aircraft in this context one or two 50 caliber machine guns provided a considerable increase in power yeah the 50 cal as we know today as sort of the armament of u.s fighters during world war ii had in fact been partially developed in anticipation that the light machine guns used in world war one won't cut it in a future war this this of course happened in uh in the 1920s america was slightly ahead of the curve in that respect and it really anticipated stronger designs in the future just requiring a strong gun to also take down of course completion's sake here during world war one heavy machine guns had already been used in aircraft uh same caliber even but less so than light machine guns and not only that but the 50 cal became relatively reliable way more reliable than those early heavy machine guns used and it was much better than the ferdikal the ferdikal really didn't cut it it was unreliable and it really wasn't suited for aerial warfare so if you look at that world war one and interwar period those 20 years give or take the 50 cal makes perfect sense yeah the switch to the 50 cal from the vertical was very straightforward which is why it happened relatively quickly and was more or less complete by the time the us is attacked at pearl harbor in 1941 even though the ferdikal is still in there somewhere it's still in there but it is really is just waving goodbye okay so that is that pre-world war ii period ticked off but then why did the u.s stick with 50 cells throughout the war second world war in their aircraft when others didn't and this is a very complex question once again because a lot of context needs to be laid out so i think that to answer this question it is best to ask another question first that question is why did the british and commonwealth forces not switch to the 50 cow in the same way as the u.s and started switching to the 20 millimeter hispano they of course used the 50 cal on planes that came from the us and later on added it to some of their planes as well like the spitfire as part of a mixed cannon and machine gun armament but the 20 millimeter became the primary fighter plane weapon this as far as i can tell had multiple reasons by the way all my sources for this video as always they're in the description below so if you want to have a look just go there there's also a lot of reading recommendations linked there as well as you know links to all my social media and so on should you be inclined to follow me there okay so let's go into this we of course have that eight gun battery on the hurricane and the spitfire that came out in the late 1930s and this made the aria think that they had a good piece and a solid piece of firepower kit under their belt and they weren't necessarily wrong eight guns in the 1930s even if they were light machine guns that's a lot for an aircraft actually yeah it's it's at least double of most competitors if not more it's a lot of firepower during the battle of britain however the raf had to fight both fighters and bombers and here the initial observation that the raf has with their free or freeze which was loosely based on the ferdical machine gun but it worked better and was an improved version let's just say [Music] their initial observation was that these eight guns on their fighters were doing just fine even against bombers however as the battle progressed the raf noticed that more and more german planes started to feature armor and that the initial accounts by pilots about the effect of their weapons was maybe a bit misleading if you ever seriously investigated kill claims and actual losses you'll notice that you will get two very different numbers and yes i know there were guidelines and how kills were claimed and scored and attributed and so on but this was not a black and white affair it really wasn't just go and you know take a look at the official records in most archives you can find them relatively easily and if you don't have access to an archive most authors and books about the subject already have a lot of examples but it's not that the pilots were not truthful as well you know of course yes we are all humans perhaps one or two claim kills that never happened there are reports that this actually did occur but by and large pilots will report what they see in good faith as the raf noticed that even with eight light machine guns they were not scoring as many kills as they thought and more crucially recognize that in most cases you only really get one chance to fire a solid burst into an enemy aircraft so you need to make it count and because german planes started getting more armor they decided that a 20 millimeter cannon would soon be necessary to defeat german luftwaffe aircraft but that is not to say that the battle of britain kick-started this process in britain the hispano had been in development for some time this battle just results into a sort of catalyst uh or things are being taken a little bit more serious it really convinces the raf that it needs to go with a cannon to essentially be future proof during this state of flux they were unsure whether a 50 cal would be enough plus being reliant on a new foreign gun and also as this armor starts being introduced nobody really could tell whether a 50 cal is going to be effective against it at most combat ranges and in most environments these protection measures get introduced into these aircraft very quickly and they start getting very very very good at defeating light machine guns and in fact by the end of the war most aircraft most german aircraft the armor that is used there is also effective against 50 cal at most combat ranges but of course in the thinking of the raf here but not just the raf or other countries if you want to be protected against enemy fire it is possible to do this against light and heavy machine guns but if you want to be protected against cannon fire you need to put so much armor into a plane that it will essentially fly like a wet dog so a 20 millimeter cannon was considered a future proof concept in britain the 20 millimeter hispano zuza cannon had been in development for some time in fact it had been in development in other countries like france before that i already spoke about this in a video once about the spitfire about its very early history with this gun with the hispano gun and the raf of course had a very difficult relationship with this 20 millimeter weapon in the early days of the war the gun would often jam and because in field tests this usually meant that after a few rounds the fighter actually had to return to base it really wasn't considered ready just yet in fact during the first time the hispano was used in combat by the raf this was really early on a spitfire armed with one gun in each wing and no machine guns attacked a german bomber and one of these hispanos jumped after only one round fire and the other one went through about half of the 60 total rounds yeah this gun wasn't ready in 1949 or 1940 but it had potential and that became ever clearer also because the raf gained experience with cannons not by using them but by being shot at with cannons and this is where we turned to the germans the german bf-109 e3 and e4 the standard fighter during the battle of britain had two 20 millimeter ng ffs based on the 20 millimeter olicum the e1 had four mt-17s the e1 did not have enough firepower that's for sure four light machine guns were really not cutting it anymore at all but some of these planes still saw service during the battle of britain also as an aside the germans actually kept two mg17s as a backup on their fighters for way too long but that's another story entirely but with the b of 109 e3 the 20 millimeter mgff gets introduced and then later on we find the mgf-m which fires a minion geshos this is essentially translated as a mine shell it's an hd round cramp of about 18 grams of high explosive content for contacts it's a lot more than over 20 millimeter hd rounds at the time the early soviet 20 millimeter hd rounds had a filling of about 2 grams yeah and this weapon proved that 20 millimeter cannons at least approved it to the germans and i think it also proved it to the brits as they were being shot at by this weapon talking about the soviet shells here by the way and also in the french and so on they drew the same conclusion as the germans although arguably maybe even a bit sooner but that's again a whole other topic and i don't want to complicate this even more so apologies if i have to push out the soviets the french the italians need japanese weapons to decide here the germans didn't have a lot of guns on their planes yeah the philosophy for the germans and for some other countries as well was that the more guns you put on an aircraft the more weight you put on an aircraft and the more weight you put on an aircraft the less performance you get unless you increase the engine performance but a stronger engine usually also increases the weight by itself so it's really with engines it's always a battle between the power the engine gives out compared to the weight of the engine and then you place that into an aircraft and certainly you have to also take into account the additional weight of the aircraft in all its equipment so it's quite a complex relationship so what they realized is if they want to limit the amount of weight they have on the aircraft they will have to rely on fewer guns and if they do that they better take guns with a lot of destructive power hence a 20 millimeter the mgf and the mgf-m and the mg151-20 and the later mk108 had a lot of bang for their weight this reduced relative weight and limited the complexity of the aircraft design and the requirement to make more space for these guns so if you could get the same or more power behind a single gun as in say four light machine guns and that single gun was still able to put out a lot of rounds in a very short term of time and have relatively good ballistic properties then that single gun was considered superior to more lighter guns now the mgf it has to be said it wasn't ideal yeah their muzzle velocity was low and it was limited to 60 rounds and drum mags and this ammo limitation was something that a lot of early cannons struggled with especially us also the hispano but it was overcome when these cannons switched to belt fit ammo or new guns were introduced like the mg151 dash trendy which was incidentally belt fed nevertheless a single hit out of any of these weapons usually meant that an aircraft a fighter aircraft was in trouble and a couple of hits usually meant the end yeah the lighter the construction of the plane usually the better it worked unless it's fabric then it might just go straight through again not a story the explosive effect which could blow holes into an aircraft's skin you know damage the system snaps cables and seriously damage the construction was very different to the machine gun which relied on making a lot of hits in key areas like the fuel tanks the engine or the cockpit so you have a trade-off either you score a few very strong hits but are limited in ammo capacity although this actually doesn't become such much of an issue anymore later on whereas the belt fit cannons get introduced or you need to score a lot of hits in the right areas to do damage as far as the germans are concerned yeah pilots usually only have a small split moment to make their shots count and you really cannot afford to tangle with the enemy so a 20 millimeter cannon becomes the best option also because the mine shell was a very good and destructive piece of kit and they did new and better and 20 millimeter mg151-20 was also around the corner so there was a future-proof system there and because this weapon worked well against fighters and heavier planes like the bombers that you see around this early war time for the raf the three or threes like machine guns they worked long enough but they also anticipated that with increasing protection especially bombers it won't be good enough anymore and even against fighters the opportunities to score a killing burst was low with such machine guns you know other than with cannons i think you can also see the thinking of the raf and trying to optimize the 20 millimeter hispano to deal with protection like armor because they went a completely different route than the germans the germans initially used both armor penetrating and he rounds on their mgff when the mine shell appeared the minion geshos with the mgf-m the ap around 20 millimeter ap round never really fully disappears but it is pushed aside the mine shell with that 18 grams of high explosive filler operated either on a contact fuse or on a slight delay fuse a really a tiny delay which was meant to blow out portions of the enemy aircraft as the round sort of digs itself into the skin and destroy components with explosive force this worked really rather well and the germans stuck with it until the end of the war uh even using it uh this mine shell with the mk 108 the 30 millimeter cannon i will come back to this in just a second now the raf instead focused on improving the armor protection of this panel by first going with an ap round good at destroying and blowing solid but small holes into fuel tanks or engines this round had the advantage of going through a lot of material during its path unlike the hd round which generally exploded on impact the disadvantage is that if you don't hit a key point the hispano ap round has so much force behind it that it would go in one side of the fuselage or wing and leave on the other side leaving some damage of course but nothing really major unless it hits a frame or spar or something this was certainly better than peppering an insignificant portion of a plane with mg bullets but could be improved upon but it is still reliant on hitting key parts like the engine the controls the cruise stations the cooling or the fuel tank by the way you most likely know this image it's based on famous survivorship bias coming out of world war ii i made a whole video a long time ago where i explained this and i'll link it below but to make matters short here the red dot signify where a bomber often got hit during world war ii and returned to base this is why these areas could be measured because they are visible on those returning aircraft whereas the white areas indicate the areas where damage would often result in the loss of the plane which are not measurable because the plane never got back as you can see the key areas are engines fuel tanks and the cockpit hit anywhere else especially if the only thing you have is a machine gun and you might as well not bother because unless you are very very lucky and shred a control cable or something very low chances you're not going to do much also generally it is impossible to protect all the vulnerable areas especially with armor which is very heavy which is why it was reserved for pilots and crew but you could at least strengthen or at least add some secondary protection to these vulnerable areas to protect a protected or self-sealing fuel tank for example is still better than just a plain fuel tank even if it gets penetrated and you can add other measures like co2 based fire extinguishers for example into engines so i know that i'm still not talking about the us here but just hear me out the context here is quite important now we'll be approaching the us in just a second so the raf had a cannon that had punch with a good ap round but it still could be improved on incendiary compounds were also added this is sometimes known as sap or zap semi armor piercing this combined the penetration of the spanner round which was good with a small explosive filler this way not only would it be more dangerous when heading an engine a fuel tank but you would still do some damage when hitting a different area entirely even if it's not a non-critical area there is of course also the discussion what was better at british hispano or german mg151-20 but again such a discussion is usually more about cherry picking both guns and crucially the ammunition worked differently fulfilled a different purpose and did that purpose very well but they also operated on the same principle being able to dispatch an enemy plane quickly with a few hits rather than having to fire a full volley into him to increase the chances of hitting a key area vulnerable area often enough with a very small less destructive round also it's important to remember that in world war ii the average accuracy in aerial gunnery was low much lower than commonly fought i know some people might point to special pilots renowned for their accuracy but one or two pilots don't win a war even 300 aces don't win a war as the luftwaffe will tell you you have to look at the full picture and average skill throughout the force some pilots got more gunnery training than others thus increasing their skill some pilots were more talented but on the whole it was very difficult to hit a small plane like a fighter and you also need to add to that the limited opportunities pilots had to actually fire their guns at an enemy in every fight if you look at some of the data on how much ammo was fired and how many kills were claimed and then look at those kill claims and then look at what can be confirmed with the real losses this becomes pretty obvious a lot of rounds were shot at a lot of targets apparently but very few of those targets went down i think one of the reasons why we have a skewed perspective on this might actually be world war two movies where planes always have to explode after a couple of rounds and world war ii combat flight simulators where we virtual pilots score hits it must be said relatively easily compared to real life and kills come more easily as well because pilots are more free to do what they want take the new il2 games for example it is not rare that many more kills are scored within a server mission that lasts like two hours than a real-life world war ii battle for air superiority over a small area for a whole day even though the amount of planes involved might not be all that different the british and germans went with 20 millimeters for their own reason which had some overlap back to the u.s the 50 cal was more destructive than the light machine guns used at the time when it was introduced in 1920s while possessing the same advantages in terms of armor supply and the ability to place it in roughly the same spot it was bigger and heavier but worth the investment initially planes had 1 then 250 cals some mixed it up with 30 cars as well of course it's only in the late 1930s and early 1940s that four then six and sometimes eight with the p-47 were installed into the aircraft for the us during world war ii this weapon was a sweet spot not because it is an actual sweet spot but because it worked for the us it would also have worked for the british most likely but it would not have worked for the germans and the japanese why we can answer this by looking at the german mk-108 a 30 millimeter cannon this weapon was introduced into german fighters with the bf-109 g6 together with two mg-131 30 millimeter heavy machine guns somewhat comparable to the 50 cal substituting the lighter mg-17s it also saw service than in other planes right why was this weapon introduced well that is because the 20 millimeter although a good gun against fighters was starting to struggle against larger machines like british or american heavy bombers it could still shoot them down but needed more hits to do so the answer to this was found in the mk108 this also fired a mine shell packed with a lot more of explosive filler and was able to do some good damage against b-17s or b-24s it wasn't the easiest gun to use but it did its job rather well there is a discussion of course that can be had if the germans had to go on the route of the hispano which had better ballistic properties than the mg151-20 and the mk-108 you know the hell arc of the mk-108 was essentially firing a mortar that's an exaggeration of course but it's not far off then maybe this would not have been necessary maybe they could have stuck with something like the hispano with its armor penetration capability but i'm not too sure about that in any case the mk108 was a light gun for its capabilities a very light gun for its capabilities in fact and it provided a lot of power and was able to take on heavy bombers that the luftwaffe had to face again often you see pictures of returning aircraft littered with holes which look impressive and are impressive especially the b17 was able to take a lot more punishment than many other planes at the time but of every plane you see there is also the other one that didn't make it now consider the targets the u.s had to face and you will see that the u.s army air force and the u.s navy had very different targets to the luftwaffe they did not face heavy bombers you know usually it was a fighter or a medium bomber from the luftwaffe or the japanese navy or the japanese army air service as such the need for a weapon that was able to take on a large strong and well protected aircraft wasn't there if it had been i am sure the us would have thought more about cannons and would have used their spinal more often and quicker once it started working properly but it didn't need to the 50 cal was good enough in the targets that the us faced but this also rested on the fact that the us placed six or eight guns on a fighter with a good ammo load and good ammunition had there been less machine guns on these planes they would not have been as successful 450 counts on the other hand and we have some evidence of this during the war we're still somewhat limited and considered not enough six or eight was good or better respectively this is where we can compare a few of the guns in a more data-like approach here we have the 30 cal the 303 the 50 cal the mg131 the mg151-20 and the mk108 i've taken the data here from anthony williams and dr emmanuel gusta they have a lot of it and do a good job at explaining the issue in their book as well we start by weight you can see that the 50 cal is a heavy weapon and weighs more than twice the 30 cal it is considerably heavier than the similar mg131 and compared with canons it is sure actually it's more half the weight than the mg151-20 and about half of the 108 yeah just imagine that a 30 millimeter cannon being about double the weight of a 50 cal that just explains to you how light the mk 108 actually was and at the same time how heavy the 50 cal was as for rate of fire it is midfield muzzle velocity is good which makes the gun a bit easier to use projectile weight well the 50 cal scores well for machine gun but you really can't compare it here to cannons or light machine guns because of the weight scaling it's best to compare it here with a similar caliber like the mg131 the power to weight ratio how much power does the gun put out compared to how much it weighs also leaves it in midfield looking at this the 50 cal does not look impressive it looks like a gun that does not have a standout feature save perhaps its muzzle velocity it's heavy and it's slow compared to the direct competitors but here is where that data can be misleading if we don't place it into the context which is why i didn't want to add this sort of chart at the beginning and why i don't like comparisons based only on this sort of data it invites cherry picking sure enough one on one the 50 cal is not the most efficient gun for its size and weight even though a comparison like here across multiple calibers is useless without that context that i talked about but here we are ignoring the influence of the ammunition fired which is rather important and 50 cal bullets uh 12.7 by 99 fired by u.s aircraft during world war ii they were good they had good you know penetration potential good ballistics and there were many iterations you know from pure black tip ap or with an incendiary compound and there was plenty of force behind these rounds not as much as yeah sure not as much as a 20 millimeter ap round from an hispano but again that's useless in a one-on-one comparison between two very different weapons as well as that the 50 cow had some logistical advantages nearly all u.s aircraft used the same ammunition this made production straightforward that is not to say that the 50 cal didn't have some limits as well and generally at point length range it could easily penetrate the armor that you see on fighters around this time but at combat ranges this is less likely especially as the rounds actually have to tumble through the aircraft before they hit the armor plate most german pilots could rely on the armor behind them protecting them from 50 califire in most scenarios a 20 millimeter ap shell on the other hand would go through that piece of armor more often than not the 50 cal rate of fire was also a bit low compared to other guns of its calendar and rate of fire helps you to concentrate a lot of rounds on a small area rather than sort of spacing them out right of course if you have six or eight guns you'll still hit with a good number of uh of your bullets even if your rate of fire isn't that ideal also us planes didn't fire one of these guns to every 20 millimeter cannon fired on a german plane but they fire two three or four fifty cals per german cannon depending on the planes we compare this is just a comparison about who has more guns or better guns you know like playing top trumps and winning because your plane has more guns than the other plane even if all you have are 20 nerf guns strapped to a glider and your opponent has a light machine gun on a cessna you know i mean sure you can put your bets on that but what sort of comparison is this we need to look at the actual use of these weapons for the average pilot and based on the context of world war ii this means that both sides essentially made the right choice give or take a few apples and one gun is never going to be ideal in all scenarios but overall they made the right choices perhaps never the ideal choices like i said but it worked for them also some pilots might say they think the 50 cal was better others would prefer the 20ml that's possible but that only means that it was the weapon this pilot preferred and on the whole there were actually very few pilots that had a chance to compare us50 cal and german 20 mils and certainly not when they were able to do so they were certainly not able to do so in combat commonwealth pilots might be able to weigh in a bit comparing 50 cals to s panels but they also use these weapons differently to us pilots so again context is both king and queen let's take another contextual example the 50 cal was also a weapon that got a solid reputation for ground strafing on the western front u.s fighter bombers used their 50 counts against german soft targets like trucks very effectively they were very effective in taking those targets out and this made things really difficult for the germans and france in 1944. in this scenario they were good in taking out soft targets like trucks they were not good at taking out tanks you know a 50 cal bullet will not knock out a tank a tiger tank by magically bouncing off the ground under the tank i know at least there's at least one documentary that makes it sound like this but if you just think and think about and you know how bullets interact especially with the ground and with our targets you'll notice that this is not possible sure enough german focus 119s also used their multiple 20 millimeter cannons for strafing especially on the eastern front against trucks and they were successful just like british planes using 20 millimeters on the western front in 1944 along with the americans were also successful in taking out soft targets this shows that all three weapons although very differently can work equally well if employed right and the best way to judge the relative weapon is to look at how it was used why it was used like this and whether it was able to do its job rather than comparing apples with oranges so to sum this up i think i've gone on for some time but to sum this up germans went with a cannon because they wanted to have as much potential behind a small number of guns which reduced weight and yes this is also roughly the case if we include the ammo a mgf weighed about as much as a single 50 cal and one mg151-20 weighed less than 250 cars while arguably delivering more destructive force and because the germans considered that in the average dogfight a few good hits with a cannon are more likely provided has a good rate of fire then a lot of hits with a machine gun while also delivering more power per hit and for them cannons were a way to go and they weren't wrong as the war went on they increased the amount of cannons and the caliber because of the targets they started to face which were mainly heavy bombers that really was their primary target at this point at least on the western front and on the whole it worked of course a p-47 like fighter aircraft could also soak up a few 20 millimeter shells and perhaps a cannon a cannon like the hispano would have been better here as well but that's the case by case in comparison but even then if the p-47 got hit by a few 20 millimeters and it didn't get shut down usually it had to fly home and took no longer part in the fight yeah something a smaller caliber gun on a german aircraft might not have achieved so there is actually a very good account of this in the book thunderbolt by robert johnson was the us fight race in one of his missions he gets hit by a german plane with cans his p-47 can still fly it is struggling a bit but it can still fly and he starts heading home he is at this point essentially a mission kill for the germans he's not shot down but he's out of the fight on his way back a fw190 spots him and starts shooting at him again but this german has no more cannon ammo he already expanded everything on a bomber well we don't know and he's only firing his machine guns and from the sound of it it was light machine guns so like the 7.92 of the mg-17s and he fires all that he has these two machine guns with all the ammo that he still has into johnson's from the bolt which keeps on flying and makes it back there is no doubt that if instead of having two mg17s if the wolf 190 only had a single 20 millimeter cannon left well he would have at least have two because that's how it was built but let's say one jammed but if he had only a one 20 millimeter cannon left with some ammo johnson would most likely not have made it back and this story just shows how ineffective a light machine gone round which had been the standard since 1916 to like the mid to late 1930s had become and every nation had found their own way in dealing with this problem uh by the way i don't think if you for example take a 190 a8 a late version of the wolf anton series with two heavy machine guns and four 20 millimeter cannons as standards there is no argument that you can make that it is not applying a more destructive force on a target in a single burst than a six-gun p-51 or even an eight-gun p-47 but that amount of destructive force a wolf 190 had to pump out had to pump out due to having to shoot down heavy bombers was far higher than what a p-51 or p-47 whom really only faced 490s or at most medium bombers had to have germany managed to compensate for the bomber threat which really is a specialized task by using a number of cannons of higher caliber to increase the chances of a one pass one kill on heavy bombers hence for example while the me2 x2 came out with four 30 millimeter mk108s although it had very early on been planned to have something like in the realm of two 20 millimeter cannons there there's a couple of proposals but two 20 millimeter cannons had been anticipated at one stage to as it was meant to be mainly a fighter on fighter platform and not going against bombers and i'm not talking about the you know the bombing thing with this aircraft that's again another topic you could say that in the me262 the germans paired their philosophy of using gun that has a high destructive potential with the u.s way of thinking of using more guns the results were four 30 millimeters which really propelled the me 262 into a league of its own it is an outlier you know usually usually planes couldn't get this sort of firepower without the use of gun pods which is really suboptimal because it hits the performance the us on the other hand decided that the best way to go was to place a lot of heavy machine guns into the aircraft which had good overall performance and any deficiencies could be compensated for by more guns and more bullets the u.s was never put into a position where a new target like a heavy bomber appeared that required a change in weaponry as such for world war ii the 50 cal was a good weapon for us aircraft you know it was it was an excellent weapon for us aircraft based on their operational tactical needs uh you might judge it as good enough or just right depending on how you look at it it was a solid piece of kit to standardize around for the time but just like for the us 20 millimeter cannons and 30 millimeter cannons was a solid piece of kit to standardize around for the germans however even going back to the u.s now even by the end of world war ii the us was investigating the possibility of switching to those cannons yeah part of this was because also combat experience showed that the chances of hits are low in an ever faster paced aerial combat scenario you really should make sure that the hits you get with your guns can apply the most destructive effect possible per hit and that really should be more than with a 50 cal commonly the korean war is here taken as the reason why the u.s made the switch in actual fact it actually started way earlier um really it's a process that kickstarted with world war ii uh but the development of homegrown cannons um which actually started doing the war took some time the us really wasn't prepared to change horse in world war ii which makes sense it took perhaps a bit long for the switch to finally happen korea probably accelerated process but to say that korea was the reason the u.s started to develop an aircraft cannon is wrong but anyway that's yet another topic and i've gone for long enough so let me know what you think about this topic and i do hope that you enjoyed this video if you did please consider supporting the channel via patreon or channel memberships uh supporters they'll also get some extra sneak peeks and can watch new videos before anyone else as always i hope all of you guys have a great day and see you in the sky

Channel: Military Aviation History

Views: 596,125

Rating: 4.8952236 out of 5

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Id: AQS6Ub5ekFE

Length: 56min 4sec (3364 seconds)

Published: Thu Mar 11 2021

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[u/OldCodger39]

Weight of shot!