P-51 would be devastating weapon of war in this game.

[Sternjaeger]

it was, that's why by the end of the war they even ditched majority of the .30 cals in favour of the .50. One round for all of them, which was also improved in its design over the war period, so much so that all the .50 cals produced were of "aircraft quality standard", and we're talking about surely the cheapest round to produce in its segment.

 

So yes, whilst a cannon round had a more destructive power, the .50 cal was (and still is)the most cost-effective and adequate HMG round available.

Edited January 11, 2014 by Sternjaeger

[79_vRAF_Friendly_flyer]

1940s America was very much in the business of mass production and supporting an Army and Navy with their accompanying air forces in several major theatres of war requires a huge amount of logistical support. The way that you partially solve this is by keeping your weapons and ammunition fairly common

 

If your argument had been over land-troops, where small units of men would occasionally have to fight isolated for days and even weeks (Bastogne springs to mind), your argument would be good. Air warfare is very different though. A plane does not plop down in the field to be armed and tanked by any passing unit. They fly back to well prepared airfields where a whole squad of men see to the needs of each single aeroplane. This airfield is usually well away from enemy lines where there are less confusion and urgency.

 

The ammo spending of each plane is also quite limited (a P-51 with 6 guns carried no more than 1880 rounds, a Tempest had a mere 800 rounds at it's disposal). I have never seen anything indicating the single Hispano of the P-38 caused any form of problem, neither that the mixed armament of the early US fighters caused problems. Heck, even the US army had .50BMG, .30-06, .30 carabin, .45ACP and even 9mm Parabellum (some of the M3 Greas guns were chambered for the German round), without really running into logistic problems. If the army could work with such a diversity of rounds, surely the air-force would not have been overly bothered by having two types of weapons and cartridges around?

 

Again, if we are to believe Chinn, the reason the US put M2 Brownings on all their fighters was because it was the only reliable gun with adequate destructive power they had access to. The switch from .30s to .50s on the bombers, likely reflects the need for better defensive armaments as fighters grew even more heavily armed throughout the war, rather than any need for standardization.

Edited January 11, 2014 by 79_vRAF_Friendly_flyer

[Sternjaeger]

If your argument had been over land-troops, where small units of men would occasionally have to fight isolated for days and even weeks (Bastogne springs to mind), your argument would be good. Air warfare is very different though. A plane does not plop down in the field to be armed and tanked by any passing unit. They fly back to well prepared airfields where a whole squad of men see to the needs of each single aeroplane. This airfield is usually well away from enemy lines where there are less confusion and urgency.

 

The ammo spending of each plane is also quite limited (a P-51 with 6 guns carried no more than 1880 rounds, a Tempest had a mere 800 rounds at it's disposal). I have never seen anything indicating the single Hispano of the P-38 caused any form of problem, neither that the mixed armament of the early US fighters caused problems. Heck, even the US army had .50BMG, .30-06, .30 carabin, .45ACP and even 9mm Parabellum (some of the M3 Greas guns were chambered for the German round), without really running into logistic problems. If the army could work with such a diversity of rounds, surely the air-force would not have been overly bothered by having two types of weapons and cartridges around?

 

Again, if we are to believe Chinn, the reason the US put M2 Brownings on all their fighters was because it was the only reliable gun with adequate destructive power they had access to. The switch from .30s to .50s on the bombers, likely reflects the need for better defensive armaments as fighters grew even more heavily armed throughout the war, rather than any need for standardization.

 

it's about logistics mate. If you need to cater for just one type of round, imagine how simplified your life would be: production, transportation, distribution, training. As per the P-38, I've read that the cannon did jam indeed (for the record, the M3 9x19mm conversion was just for the OSS, it didn't see active service with troops).

 

Regarding the best ammunition available, you have to bear in mind that the US did a lot of R&D with guns and ammo (the development of the M-1  Garand is a typical example of that), but yes, as you said the .50 cal for aircraft use was the best of what was available. 

 

It's interesting to note that whilst the Navy quickly converted to 20mm (probably because they needed a gun with more destructive power, in order to use their aircraft for multiple roles, i.e. ground attack even without rockets or bombs), the air superiority work done by the USAAF/USAF was continued using the M3 (which is an AN-M2 with a higher rate of fire). 

 

So it still remains that the superior ballistics of the .50 cals were preferred for accuracy and rate of fire, and still managed to be effective even on 50s jets like the F-86 Sabre. 

 

Talking of the F-86, it's interesting to see how the licensed-versions of the Sabre received the 30mm Aden cannon conversion (think of the CAC Sabres, which were meant for ground attack), whilst for the USAF it's not until the F-86K that the 20mm M24A1 cannon was regularly introduced. 

[JtD]

Logistics isn't just about avoiding problems, but also about keeping the war running with the minimum effort necessary. Having your air force use a single gun with say 3 different types of rounds makes it much easier to maintain than an air force using 10 different guns with 30 different types of rounds. The effort you save manufacturing, organizing and distributing the weapons and ammunitions can be spend for other, more important things.

 

I'm with IceFire here, the simplified logistics were a huge plus and certainly part of the decision about using the gun to the extent it was used.

[79_vRAF_Friendly_flyer]

Actually, the US did not standarize on .50s. In planes where the pilot could reach the breech (the P.38) or where the fighters needer a better all-round gun (the Corsair), they did accept the US made Hispano, warts and all.

 

If we are to believe Chinn (and I see no-one here refuting his claims), the air force of the US did not want their fighters armed with M2 Brownings. They ended up in a situation where they had to stick to the M2, not out of choice, but because a reliable gun with more destructive power were not available to them. They certainly planned for converting to Hispanos, they just never were able to. As for for logistics, by 1944 there were millions of 20 mm rounds rotting away at US arsenals, more then enough to arm every US fighters had they been equipped with Hispanos.

 

So yes, the "decision" to go for full .50 fighter armament was a matter of logistics, but only in that you don't want guns that regularly fail in wing mounted armament. It was not because supplying parts and ammunition for such a gun would be be a needless drain on the US supply lines. The gun and it's ammunition was actually already in the supplies, only destined for the navy and for land troops where the soldiers could reach the breech in case of a misfire.

Edited January 12, 2014 by 79_vRAF_Friendly_flyer

[JtD]

Do you really believe that, while the Germans introduced the MG 81, MG 131, MG 151, MG 151/20, MG FF/M, MK 108, MK 101, MK 103 and possibly a few more during WW2, there was a dire need in the US for a bigger gun than the 0.50 and while they tried their best, it was due to incompetence of US technical staff that it wasn't available until after the Korean war?

[79_vRAF_Friendly_flyer]

Do you really believe that, while the Germans introduced the MG 81, MG 131, MG 151, MG 151/20, MG FF/M, MK 108, MK 101, MK 103 and possibly a few more during WW2, there was a dire need in the US for a bigger gun than the 0.50 and while they tried their best, it was due to incompetence of US technical staff that it wasn't available until after the Korean war?

 

The need obviously wasn't dire enough (US fighters mainly fought fighters), so they made do with the M2. The point is that the M2 was adequate, but hardly a stellar, aeroplane armament. The US could have gotten a lot more destructive power for the same weight had they had access to a more reliable auto-cannon.

 

As for the incompetence, it seems more to be a minor initial error never been fixed due to multiple responsible authorities, several different makers and possible some pig-headedness. There's no need to question what I might believe (I wasn't there), I'm just quoting the USN Bureau of Ordnance:

 

http://www.ibiblio.org/hyperwar/USN/ref/MG/

 

Feel free to point out where Chinn got it wrong.

[JtD]

Am I to understand that while you're referring to Chinn, you don't actually share his point of view?

 

Could you please save me some time and point me to the part of Chinns work where he says logistics played no part in the preference of the 0.50 for aircraft armament? Personally, I don't recall having read that, but I might have forgotten about it.

[sturmkraehe]

Actually, a set of 6 or 8 .50 M2s are quite less devastating than a typical comparable set of cannons, if we are to believe the calculations of Williams & Gustin (http://www.quarry.nildram.co.uk/WW2guneffect.htm), the armament of a 6 gun late war Mustang had about a third of the destructive power of a contemporary Tempest (four Mk.V Hispanos). One may disagree with W&Gs parameters, but as they have stated, fiddling with the values up and down changes point scores, but not really the order in which the destruction powers of the various guns rank.

 

Being less devastating is not a critique of the gun itself, it won't make sense to overload a fighter with guns to the degree it can't fly (heavily armed bomber interceptors tend to be poor dogfighters). Clearly, the 6 or 8 .50s were adequate for the job they were put to. They did weight a bit however. 6 M2 HMGs weigh about the same as 4 Hispanos, for less than half the destructive power. This means that had the Americans been able to field a reliable version of the M3 Hispano, the Mustang could have enjoyed the destructive power of the Tempest for the same weight.

 

If you read the chapter of Chinn's book that I linked to further up, you will see that regarding the .50s as 'more effective' than cannon' certainly was not a sentiment shared by the USN Bureau of Ordnance, and appear to be more of a post-war myth. Granted, the Browning M2 was 'more effective' than the American made Hispanos with regard tof technical efficiency, but not with regards to destructive power.

 

 

 

 

In the 1950s, the war was over and production was geared over for peace. I imagine re-arming all American fighters with a new gun was very low on the priority list. However, as soon as the Korean War heated up, the change from .50s to 20 mm cannons came very quickly.

 

I think the 8x .50 cals was a very good gun setup for the purpose and the condition for which it was used. 

 

1. We should consider that the American fighters' principal mission was to protect the bombers. This implies that they primarily had to take care that no enemy fighter could shoot at a bomber. This can certainly be achieved in attacking the enemy fighter so the latter has to defend himself rather than continue to go for the bombers. Along with the purpose of breaking up any enemy attack formation in order to prevent a coordinated attack on a bomber formation. If all enemy fighters are occupied defending themselves the primary goal was already achieved. As a second step the enemy fighters have to be prevented from reforming and launching a second wave of attacks on a bombers. This can be obtained in three ways: To scare them away (probably not well working for disciplined pilots - perhaps rookies however); to damage them so they have to fly back; or to shoot them down (with the side effect that this plane is to be written off). Hitting the plane will do one or the other. So it was probably efficient to have guns that due to high rof and good ballistics were comparatively easy to obtain hits with them with the potential to even damage the plane beyond repair or to shoot it down.

 

2. Soon after the appearance of the US on the European theatre of war, the US airforce outnumbered the Luftwaffe as far as I know mutliplying thus the guns pointing at each Luftwaffe plane (whose pilots were less and less well trained).

[79_vRAF_Friendly_flyer]

Am I to understand that while you're referring to Chinn, you don't actually share his point of view?

 

Could you please save me some time and point me to the part of Chinns work where he says logistics played no part in the preference of the 0.50 for aircraft armament? Personally, I don't recall having read that, but I might have forgotten about it.

 

No, I do share his point of view, or rather, he is the only author I've read who presumably know what ha talks about who has written anything about the .50 vs 20 mm controversy. I suppose the correct term would be that i "trust his judgement".

 

I never claimed Chinn says logistics didn't enter into it, only that the chief reason the US did not switch their somewhat lacklustre fighter armament for something more effective was primarily because they could not get their Hispano reliable enough for general aircraft armament deployment. Quite a few of the others here say the .50 is better suited for fighter armament than 20 mms, but they have failed to back up their assertions with sources, or to address any error in Chinns writings.

[JtD]

Well, OK, I was only arguing the point of logistics, which I understood you said did not matter at all.

 

On your point, I'm not sure that the Hispano had replaced the Browning on a large scale had it been as reliable. Technically it would have been better, but the Browning got the job done. Never change a working system. However, the trend towards the cannon was there already, and I suppose it would have been more pronounced with a reliable cannon. How much more is hard to say. The P-51 initially came with Hispanos. Do you know why it was swapped for Brownings?

[Sternjaeger]

Actually, the US did not standarize on .50s. In planes where the pilot could reach the breech (the P.38) or where the fighters needer a better all-round gun (the Corsair), they did accept the US made Hispano, warts and all.

the use on Corsairs and Hellcats was marginal, the only substantial use was on the P-38 and P-61, and they caused problems.

 

If we are to believe Chinn (and I see no-one here refuting his claims), the air force of the US did not want their fighters armed with M2 Brownings. They ended up in a situation where they had to stick to the M2, not out of choice, but because a reliable gun with more destructive power were not available to them. They certainly planned for converting to Hispanos, they just never were able to. As for for logistics, by 1944 there were millions of 20 mm rounds rotting away at US arsenals, more then enough to arm every US fighters had they been equipped with Hispanos.

..do you realise that the so called "Navy 20mm" that was introduced right after WW2 was in fact a re-designed round and above all casing, which had still the same length (110mm), but had a slightly larger and conic shape? The 20x110mm HS produced were all sent to the British or used 

 

 

1) 20x110 US Navy (designed in WW2 and introduced afterwards to compensate on the problems of the original design)

2-5) 20x110mm Hispano Suiza

6) 20mm Oerlikon

 

So yes, the "decision" to go for full .50 fighter armament was a matter of logistics, but only in that you don't want guns that regularly fail in wing mounted armament. It was not because supplying parts and ammunition for such a gun would be be a needless drain on the US supply lines. The gun and it's ammunition was actually already in the supplies, only destined for the navy and for land troops where the soldiers could reach the breech in case of a misfire.

it's ludicrous to think that a power like the US didn't do their R&D with ammunition and guns. They indeed did A LOT of research, and tried different calibres (look at the development of the P-38 lightning for instance, which was used as testbed for quite a range of guns). The M2 proved to best the best all-rounder, and the reliability issue was fixed with simple but effective modifications to the casing (i.e. the insertion of three grooves around the primer).

 

The M2 is a gun with incredible longevity (it was introduced in 1921) because of its qualities, the only other calibre that survived comparatively long is its russian counterpart, the 12.7x108mm, introduced in 1934.

[79_vRAF_Friendly_flyer]

P-51 initially came with Hispanos. Do you know why it was swapped for Brownings?

 

Reliability problems with the US made Hispano M2 guns? My guess is as good as yours. I guess the initial cannon armament reflects the Air Force's expressed preference for cannon armament for future fighters, only swapped to HMGs when no reliable cannons were available.

 

 

 

the use on Corsairs and Hellcats was marginal, the only substantial use was on the P-38 and P-61, and they caused problems.

 

...

 

it's ludicrous to think that a power like the US didn't do their R&D with ammunition and guns. They indeed did A LOT of research, and tried different calibres (look at the development of the P-38 lightning for instance, which was used as testbed for quite a range of guns). The M2 proved to best the best all-rounder, and the reliability issue was fixed with simple but effective modifications to the casing (i.e. the insertion of three grooves around the primer).

 

Yes they caused problems, which is sort of the point I have tried to make. In fact, they were so unreliable they could only satisfactory be installed in aeroplanes where the pilot or crew had access to the breech to re-cock the striker in case of a badly struck round. The special need of the Navy where fighters would have to conduct ground attack work and stop torpedo-bombers or even kamikaze attacks mandated cannons to the degree they were willing to put known unreliable guns on fighters in preference to .50 MGs.

 

As for the US R&D, they certainly did a lot, but they still failed to iron out the problems of the US made Hispano during the war. If I were to speculate, I'd say the heavy investment they had made in the Hispano from 1937 on made it difficult to swap it for a wholly different gun during the critical years (from 1942 to -45). The wish to retain a gun that had the same ammunition as the British is also mentioned by Chinn.

 

I'm interested in the three groves you mention. When did it take place? According to Chinn it was the electrical priming of the post-war M24 that finally solved the reliability problem.

[Sternjaeger]

Reliability problems with the US made Hispano M2 guns? My guess is as good as yours. I guess the initial cannon armament reflects the Air Force's expressed preference for cannon armament for future fighters, only swapped to HMGs when no reliable cannons were available.

 

that, plus the fact they could carry more ammunition, having a longer firing time (which, believe it or not, is what pilots wanted). The truth is that the Hispano wasn't the only available cannon: the Oerlikon for instance was also available, and despite its widespread use as anti-aircraft gun (and the Japanese made use of a licensed version as aircraft cannon as well), it was deemed as unsatisfactory for aircraft use. One wonders how much policy was involved in the thing as well... it is interesting to note that majority of the guns used by the USA were of American design and production, and this could have also played a part in the final decisions.

 

Yes they caused problems, which is sort of the point I have tried to make. In fact, they were so unreliable they could only satisfactory be installed in aeroplanes where the pilot or crew had access to the breech to re-cock the striker in case of a badly struck round. The special need of the Navy where fighters would have to conduct ground attack work and stop torpedo-bombers or even kamikaze attacks mandated cannons to the degree they were willing to put known unreliable guns on fighters in preference to .50 MGs.

not sure the Hispano could be manually cocked from the cockpit, but I'll check.

 

As for the US R&D, they certainly did a lot, but they still failed to iron out the problems of the US made Hispano during the war. If I were to speculate, I'd say the heavy investment they had made in the Hispano from 1937 on made it difficult to swap it for a wholly different gun during the critical years (from 1942 to -45). The wish to retain a gun that had the same ammunition as the British is also mentioned by Chinn.

I think the main reason was that it's not just about the guns you design, but it's that you need to adapt the aircraft in order for them to be used. The Hispano is a big bulky bugger, and if you take the mustang, it would have been impossible to redesign the wing whilst maintaining the aerodynamical characteristics of the wing.

I bet the Allies were in for a shocker the first time they put their hands on a Mk108 cannon!

 

I'm interested in the three groves you mention. When did it take place? According to Chinn it was the electrical priming of the post-war M24 that finally solved the reliability problem.

It's called 3 stab primer crimp to be exact, and it can be seen on the first two rounds below. 

 

 

one of the main causes of misfires was related to primers falling off the round (because they were rattled around a lot), which a ground soldier or defensive gunner could have easily fixed by re-cocking his gun, but it would have rendered a wing-installed gun unusable. The simple but effective solution was to crimp the primer in place, ensuring that it wouldn't be lost and dramatically reducing the misfire incidents. 

 

Ammunition "for aircraft use" became a standardisation not just for tolerances and materials (the Germans for instance used brass exclusively for aircraft use ammunition at first, and the round was identifiable by a little star on the headstamp), but also for the small modifications like crimping.

 

This sort of crimping became a standardised production procedure, so all ammunition produced by the US was of "aircraft grade". 

 

Electrical priming, introduced by the Germans, was the next step, but again the Allies managed to develop it only with the late US Navy 20mm cannon, which was in use from the very late 40s onwards. 

[gavagai]

Read Tony Williams on the 50 cal Browning.  You won't find many opinions as informed as his:

 

 

The American Browning .50 M2 is an undistinguished performer, particularly when compared with its closest competitor, the 12.7 mm Berezin. The relatively small incendiary content in the .50 API (0.9 g instead of 2 g) gives the Soviet round a flying start, which it adds to by its usefully higher rate of fire, then finishes off in style by being lighter as well, and thereby almost twice as efficient overall. The Browning also makes an interesting comparison with the Japanese Ho-5, which was basically the M2 slightly scaled up to take 20 mm cartridges.

It may appear that this low score of the .50 M2 is in disagreement with the satisfactory experience the USAAF had with this weapon. The answer to this apparent contradiction is that the .50 M2 proved very effective against fighters and (not too sturdy) bombers, if installed in sufficient numbers. Six or eight guns were specified as standard armament, resulting in a destructive power total of 360 or 480, at the cost of a rather high installed weight. Most American fighters were sufficiently powerful to have a high performance despite this weight penalty. Incidentally, the mediocre efficiency score of the .50 M2 is not only an effect of the low chemical content of its projectiles. Even if only the kinetic energy were considered, the efficiency of this gun would remain inferior to that of the UBS, B-20, ShVAK or Hispano, although better than that of the MK 108 or MG-FFM. To sum up, the preferred US armament fit was effective for its purpose, but not very efficient by comparison with cannon.

 

http://www.quarry.nildram.co.uk/WW2guneffect.htm

[Sternjaeger]

I don't always agree with Tony Williams and his conclusions, he often omits factors like convergence in his considerations on effectiveness.

Edited January 13, 2014 by Sternjaeger

[79_vRAF_Friendly_flyer]

The truth is that the Hispano wasn't the only available cannon: the Oerlikon for instance was also available, and despite its widespread use as anti-aircraft gun (and the Japanese made use of a licensed version as aircraft cannon as well), it was deemed as unsatisfactory for aircraft use.

 

...

 

 

I think the main reason was that it's not just about the guns you design, but it's that you need to adapt the aircraft in order for them to be used. The Hispano is a big bulky bugger, and if you take the mustang, it would have been impossible to redesign the wing whilst maintaining the aerodynamical characteristics of the wing.

 

This Oreikon was unusable for aircraft use without some very heavy modification. The Orleikon fires from an open bolt. That means it is the inertia of the bolt that keeps it from opening too soon, which again necessitates a very heavy bolt. The vibration alone from that heavy bolt would be detrimental to life span of the gun mount, not to say wing structure. The Orleikon was the starting point for several aircraft guns though, the MG FF was made manageable by lightening the load to the degree the bolt could be light enough for aeroplane installation (at price of low muzzle velocity), the Bikight solved it by locking the bolt, unlocking it during firing by gas siphoned off from the barrel (similar to the M-16 mechanism). This eventually developed into the Hispano.

 

The first Mustangs were actually given Hispanos (Mk. II), so there's obviously nothing inherently impossible with fitting them. The M2 is a fairly bulky gun itself, so fitting two Hispanos rather than six M2s should not be too much problems, particularly not when belt feed was developed. Might have needed two blisters though, but they won't ruin an aeroplanes performance.

 

.30 Browning, .50 Browning M2 and two long barrelled Mk. II Hispanos with drum feed. Loose the drum, and you have a fairly slim weapon:

 

Edited January 13, 2014 by 79_vRAF_Friendly_flyer

[79_vRAF_Friendly_flyer]

Sorry, the grey drum above is the belt feed.

 

Hispano and M2 installation in a Spitfire wing, comparison:

 

Edited January 13, 2014 by 79_vRAF_Friendly_flyer

[Sternjaeger]

the H/S was an open bolt cannon as well, and you would have lost the laminar wing profile to install it. 

[79_vRAF_Friendly_flyer]

No, the Hispano fired fro a locked bolt. That's why it could have decent ballistics without being too heavy.

[Sternjaeger]

you are right actually, it was a locked bolt design, sorry. The problems it had were inherent to the chambering and extraction processes, other than the often occurring "light striking" of primers, resulting in a misfire and stopped gun.

[JtD]

Reliability problems with the US made Hispano M2 guns? My guess is as good as yours. I guess the initial cannon armament reflects the Air Force's expressed preference for cannon armament for future fighters, only swapped to HMGs when no reliable cannons were available.

I didn't look for guesses, and so I won't be guessing myself. I think it would shed some light on the issue if we knew the true reason.

 

The only first hand account I've read on the issue has neither to do with reliability nor logistics. In the joint fighter conference in 1945, a Navy officer asked an Army officer why the Army was sticking with the 0.50, because the Navy didn't understand. Simply put, the Army guy said that the 0.50 round is effective against the targets it is used against, and that the Army prefers to fire as many effective rounds as possible, mainly for better hitting chances with poor and average pilots behind the stick.

[79_vRAF_Friendly_flyer]

In the joint fighter conference in 1945, a Navy officer asked an Army officer why the Army was sticking with the 0.50, because the Navy didn't understand. Simply put, the Army guy said that the 0.50 round is effective against the targets it is used against, and that the Army prefers to fire as many effective rounds as possible, mainly for better hitting chances with poor and average pilots behind the stick.

 

Some officers may certainly have felt that way, I'm not sure if it stands up to scruteny though. Bear with me:

 

A pilot is able to keep the enemy in true sight a certain portion of the time he fires his guns. In any situation, a certain percent of the rounds fired will hit the enemy plane. If you have many guns firing a high number of bullets, that number will be high, if you have fewer guns with a lower ROF, then fewer projectiles hit home. However, unless there are really few projectiles in the air (like with the 37 mm nose canon on the Cobra), the percentage of projectiles that hit versus those that do not are more or less the same in both cases. Agree?

 

Now, if we agree the percentage of projectiles that hit for a given unit of firing time, we can look at destructive power per unit of time. Here's where Williams and Gustin comes in. If we for the sake of the argument accept their estimated destructive power of guns for true, it means that 6 M2 guns can deliver 12,6 units of destruction for a given unit of time, while the four Hispano Mk.V of a Tempest can deliver 24,0 units of destruction at the same time. If we say only 10% percent of the projectiles hit home, the four Hispanos are still twice as destructive (2,4 vs 1,26). The air force officer appear not to have any greater understanding of statistics.

 

This is not to say the M2 was without merit. Reliability would have been very important in long range operations, and Sternjaeger mentioned total firing time. The Mustang had a whooping 30 seconds firing time, while the Tempest had mere 16 seconds. Still, had the Tempest had half the guns but the same amounts of ammo, it would still be as deadly as the Mustang per units of time firing, with the same amount if firing time, but substantially less weight. A big plane like a Thunderbolt could easily have four Hispanos and copious ammunition, giving it more firepower than the 8 M2s, and save weight in the process. Heck, it could even have six Hispanos and still be able to fly well.

[JtD]

You don't really have to tell me, I was merely stating what that USAF Colonel gave as the USAF view on the subject. I'd also disagree with him, but then he probably got a better idea than myself of what average and worse pilots were capable and incapable of, and what helped them to at least score a hit.

 

Just as food for thought - with a 1% hitting probability, same weight M2 battery (~7 guns) has an 83% chance to score a hit in a 2 second burst, the 4 Hispanos have a 53% chance. And still some pilots came home with their magazines empty and without scoring a hit. So there certainly is some truth to the USAF point of view.

 

I don't think the limit for firing time is just weight, there's also a room limit. The weapons guy in that conference simply stated that more than 20s of firing time with a 20mm cannon were not possible. I take it he meant it with regards to the space available in the wings, because technically there's no limit for the gun as such that I can think of.

[MiloMorai]

[Sternjaeger]

well that didn't go past testing, did it?

[Rama]

That one (prototype DP845), yes, she did past testing, she even beat the Typhoon and a captured FW190 in a test race. But the 6 guns were just placeholders.

The derived serial plane was the MkXII, generally equiped with 2 HS Guns and 4 303.

[Sternjaeger]

yeah, what I meant is that it never made it to production. 

[II./JG27_Rich]

A P-51 D is about 1700 lbs heavier than a 109 K4 and a K4 has more hp. so the way this fm works the Mustang might have a handful.

[Sternjaeger]

the P-51 is heavier, but the four-bladed constant speed prop does a great job at keeping her airborne. It's defo an energy fighter though, having said that, the clean lines mean it also gains speed faster.. it flies like nothing else, but you gotta learn her ways. One of the most interesting things about her though is that all the warbird operators and owners who I know or met who flew several kinds of warbirds, all unanimously agree that it's by far the best warbird they've ever flown 

[ImPeRaToR]

A P-47 with 6 Hispano Mk.V now that I want to see

[sturmkraehe]

Yeah the 51D is a very neat design. There had been very thoughtful engineers who were able to put everything they knew at the beginning of its development into it. Spiced up with American generosity. 

[79_vRAF_Friendly_flyer]

A P-47 with 6 Hispano Mk.V now that I want to see

 

Heck, I'd settle for a Mossie or a Baufighter with that kind of artillery in the snout, it'd still be awesome!

[MiloMorai]

A P-51 D is about 1700 lbs heavier than a 109 K4 and a K4 has more hp. so the way this fm works the Mustang might have a handful.

 

P-51s using 150PN fuel put out ~2000hp. The only K-4 that came close was the 1.98ata + C3 fuel ones and there was only a penny packet number of those in the last few weeks of the war in Europe.

[Kurfurst]

The only P-51 that had about 2000 HP in output were those few running on +25 lbs or 81" Hgmm. However the USAAF used only 72" Hgmm boost IIRC, which probably works around at 1800 HP or so (67" gave 1690 HP).

 

That being said, the 51 was a great all-around plane, probably the greatest at that.. In a strict knife-fight though, the 109s lightweight airframe and huge amounts of power gives it most of the spades.

[MiloMorai]

It was more than a few Kurfurst but then you are in denial about the wide spread the use of of 150PN fuel like you are about the extensive use of 100 octane during the BoB.

[Sternjaeger]

Gents, you can appreciate that it's not just about the HP output, these are not cars... 

[RR1357]

The only P-51 that had about 2000 HP in output were those few running on +25 lbs or 81" Hgmm. However the USAAF used only 72" Hgmm boost IIRC, which probably works around at 1800 HP or so (67" gave 1690 HP).

 

That being said, the 51 was a great all-around plane, probably the greatest at that.. In a strict knife-fight though, the 109s lightweight airframe and huge amounts of power gives it most of the spades.

I doubt that the late bf109 engine and airframe could take as much punishment as those of a p-51. This ofcourse because of the lack of high quality materials and the constant bombing of the German factories.

[Sternjaeger]

They were two different construction philosophies, the 109 was more like a Spitfire in that sense. Mind you, this didn't make the P-51 any less vulnerable!

[Venturi]

Rate of fire trumps all against fast moving targets, relatively unarmored and small fighter planes. Against slow, large, armored targets, cannon were necessary for efficient takedown. This was one of the primary reasons for European air forces' switching to cannon/mg setups from the 4x 30cal mg bf109e-1 and 6x and 8x .30cal mg hurri and spit during and after the battle of britain. American air forces, when they faced Japanese bombers in the pacific, never found .50cals lacking, and by the time they were employed against the Luftwaffe, did not have to deal with bombers at all. Thus, standardization on .50cals was simply common sense given the problematic operation, mounting, and supply brought about by introducing the unneeded power but slow rate of fire 20mm cannon setups to aircraft designs that were already set up for .50cal mounting (recall that aircraft design took several years, the P-51 airframe for instance began development before the battle of britain, in 1939).