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

[Finkeren]

Overall I think the UBS' performance is enough "in the ballpark" to give us an idea of how the M2 would perform. Sure it would have a slower rate of fire and propably be somewhat  more reliable (if/when gun jams are modelled), but ballistics-wise, it's really peanuts we're arguing over.

[Sternjaeger]

I'm not saying the M2 .50 wasn't a good gun, just that it isn't "a howitzer". It's just a heavy MG, and while very reliable, it was also quite heavy and had a low rate of fire (which is why the USAF put 6 or 8 of them in their fighters). The Berezin wore out a lot faster, but as long as it fired, I'd rather have it than an M2.

 

The AN/M2 was actually a lot better than the standard M2: the rate of fire was between 750 and 850 rounds per minute, and the lightened barrel meant the weight was only 28kg (the UB was 21kg), 10kg lighter than its ground use counterpart. Don't confuse the bog standard M2 with the aircraft use one. The fire of 6 or 8 M2s converging was indeed a howizer.

 

Higher rate of fire also means more destructive power per weight of gun. This is where the Berezin really shine: it is a light gun with a high ROF, and should be able to do some really nasty things to an enemy plane.

 

this is the main misconception about aerial gunnery: it's not about the rate of fire of a single gun, it's about how much accurate punch you can deliver in the shortest time possible. In order for two UBs to deliver the same amount of punch of 6 (or 8!) M2s, you'd need a longer burst, and this would affect accuracy, especially on guns with high dispersion as the UB.

 

Another note about the ammunition: despite the bigger load, the UB rounds had actually a slower muzzle velocity than the M2 rounds, which again affected aiming accuracy.

Edited December 16, 2013 by Sternjaeger

[216th_Jordan]

If jamms and dispersion will be implemented correctly i think the UB will have to be handled with care.

BTW: ROF of the UB ranges between 800 and 1050 from different sources (while the M2 has about 750 to 800). The gun being light also results in a higher vibration. when it comes to accuracy, damage by round and number of rounds calculated together it think the m2 and the UB are not far away from each other while the M2 still remains the more reliable gun (this guns design sure has a reason to live for a hundred years..). 

 

But what really matters is the Round and i really do know little about the ones the UB is using and what types there are, any reliable info on that?

[Finkeren]

About rate of fire: Keep in mind, that in most configurations the UBS is synchronized, which can somewhat alter the firing rate you're gonna get (though less so than was the case with WW1 systems)

 

Still, even the lower ranges for the UBS' ROF is impressive enough.

[Sternjaeger]

Rounds were quite similar actually, I'll post some pictures later of the classic AN/M2 ones and the UB ones. 

 

the US used AP (black tip), Incendiary (blue tip) and tracer (red tip)

the Russians used API (red/black tip), ball and tracer (red or purple tip)

[216th_Jordan]

The M2 also used API if i'm not wrong... could not find a reference to when it was introduced but if found a source stating it was used with the M2.

[79_vRAF_Friendly_flyer]

The AN/M2 was actually a lot better than the standard M2: the rate of fire was between 750 and 850 rounds per minute, and the lightened barrel meant the weight was only 28kg (the UB was 21kg), 10kg lighter than its ground use counterpart. Don't confuse the bog standard M2 with the aircraft use one. The fire of 6 or 8 M2s converging was indeed a howizer.

 

 

this is the main misconception about aerial gunnery: it's not about the rate of fire of a single gun, it's about how much accurate punch you can deliver in the shortest time possible. In order for two UBs to deliver the same amount of punch of 6 (or 8!) M2s, you'd need a longer burst, and this would affect accuracy, especially on guns with high dispersion as the UB..

 

I'm not sure I follow you? Are you saying the Berezin is an inferior gun because the VVs used two per plane and the USAF used 6 or 8 of their M2s per plane?

 

And a HMG is not a howitzer. It throws solid slugs. The slugs from an M2 are larger than those of your normal LMG, but they are still just slugs. Howitzers are cannons who primarily rely on explosives and incendiary material of the shell to do damage. A single hit from a typical howitzer can take out a tank or a medium sized ship. An .50 round may do bad things to a flimsy aircraft if it hits in the right spot, but a howitzer it is not.

[Sternjaeger]

The M2 also used API if i'm not wrong... could not find a reference to when it was introduced but if found a source stating it was used with the M2.

 

yes, they had also API (silver tip) and APIT (silver and red tip), but AFAIK these arrived later in the war (mid 1944 onwards). Late P-47s notoriously loaded mostly API-APIT, especially when they went out chasing vehicles. 

 

 

 

The load was normally down to the squadron/pilot preferences: I've seen pics of Mustangs with AP-AP-I-I-T sequences or AP-AP-AP-AP-T or all I.

 

Incendiaries are typically recognisable in guncam footage because they make a big flash when they hit something.

Edited December 16, 2013 by Sternjaeger

[Sternjaeger]

I'm not sure I follow you? Are you saying the Berezin is an inferior gun because the VVs used two per plane and the USAF used 6 or 8 of their M2s per plane?

 

And a HMG is not a howitzer. It throws solid slugs. The slugs from an M2 are larger than those of your normal LMG, but they are still just slugs. Howitzers are cannons who primarily rely on explosives and incendiary material of the shell to do damage. A single hit from a typical howitzer can take out a tank or a medium sized ship. An .50 round may do bad things to a flimsy aircraft if it hits in the right spot, but a howitzer it is not.

 

No, I'm saying the Berezin was an inferior gun because it wasn't reliable, and the fact that it wasn't used in the same way the Americans did made it less efficient than what it could have been. 

 

Regarding the howizer point, you're comparing kinetic (HMG) with chemical (cannon) energy, which is an inappropriate comparison, but if you want to compare them, we can say that the only edge that cannon rounds have over HMG is that one well planted HE round can be fatal for your enemy, but the disadvantages are:

 

1) you need to get close: very few pilots could master deflection shooting with cannons, which rounds are notoriously slow and with low rate of fire.

2) you carry less ammunition

3) you're more prone to have duds (there were several instances of USAAF aircraft coming home with unexploded HE rounds in their wings/fuselage)

4) a jam can be critical/dangerous

5) you carry A LOT of explosive in your wings/fuselage.

6) your ammunition is heavy.

 

it still remains that being at the receiving end of 6/8 converging 50 cals was really like a howizer: they knocked out tanks with them!

[-MG-Cacti4-6]

No, I'm saying the Berezin was an inferior gun because it wasn't reliable, and the fact that it wasn't used in the same way the Americans did made it less efficient than what it could have been. 

 

Regarding the howizer point, you're comparing kinetic (HMG) with chemical (cannon) energy, which is an inappropriate comparison, but if you want to compare them, we can say that the only edge that cannon rounds have over HMG is that one well planted HE round can be fatal for your enemy, but the disadvantages are:

 

1) you need to get close: very few pilots could master deflection shooting with cannons, which rounds are notoriously slow and with low rate of fire.

2) you carry less ammunition

3) you're more prone to have duds (there were several instances of USAAF aircraft coming home with unexploded HE rounds in their wings/fuselage)

4) a jam can be critical/dangerous

5) you carry A LOT of explosive in your wings/fuselage.

6) your ammunition is heavy.

 

it still remains that being at the receiving end of 6/8 converging 50 cals was really like a howizer: they knocked out tanks with them!

this. 

 

I will say that this has been a very interesting discussion. Everything that is listed above are some of the key reasons that the USAAF chose a high number of 50's over a low number of 20mm's. One thing to also consider that was aluded to here is the weight factor of the ammo. physical size not withstanding, you could carry only a fraction of 20mm ammo in comparison to the 50's. because of engine power and airframe size, the W&B issues that could arrise when trying to carry a large number of cannon rounds was pretty significant. This would also cut down of maneuverability as well since the a/c was heavier. American birds early to mid war were pretty much BnZ'rs. Once the corsair's, p39's (one they addressed the stall=flat spin issue), and p51's were introduced things started changing though. prior to those birds, the us needed all the maneuverability they could get. once it was determined that 50's had more punching power than anything short of a 20mm, they stuck with it. 

Edited December 16, 2013 by -MG-Cacti4-6

[ParaB]

 

it still remains that being at the receiving end of 6/8 converging 50 cals was really like a howizer: they knocked out tanks with them!

What tank could be 'knocked out' by 0.50cal rounds?

[Sternjaeger]

any sort really: a rain of API rounds like the ones loaded on the P-47 above could do a great deal of damage. You don't need to penetrate a tank to disable it: you can break the tracks, damage the engine (grilles at the top were quite vulnerable), ignite external tanks.. 

 

Some pilots allegedly said they could ricochet rounds under the bellies of the tanks and penetrate them from the bottom, which sounds a bit implausible with heavy panzers, but then again not at all impossible with lighter tanks or halftracks.

[-MG-Cacti4-6]

What tank could be 'knocked out' by 0.50cal rounds?

japanese light tanks mostly

[6S.Manu]

No, I'm saying the Berezin was an inferior gun because it wasn't reliable, and the fact that it wasn't used in the same way the Americans did made it less efficient than what it could have been. 

 

Regarding the howizer point, you're comparing kinetic (HMG) with chemical (cannon) energy, which is an inappropriate comparison, but if you want to compare them, we can say that the only edge that cannon rounds have over HMG is that one well planted HE round can be fatal for your enemy, but the disadvantages are:

 

1) you need to get close: very few pilots could master deflection shooting with cannons, which rounds are notoriously slow and with low rate of fire.

2) you carry less ammunition

3) you're more prone to have duds (there were several instances of USAAF aircraft coming home with unexploded HE rounds in their wings/fuselage)

4) a jam can be critical/dangerous

5) you carry A LOT of explosive in your wings/fuselage.

6) your ammunition is heavy.

 

it still remains that being at the receiving end of 6/8 converging 50 cals was really like a howizer: they knocked out tanks with them!

 

I disagree with every point you made except the #4.

 

If .50 cals were so better can you explain to my why the US warbird were the sole to use an HMG as main weapon?

The RAF could mount that but they stayed with the Hispanos. The Russians could copy them but they didn't.

 

I agree that it's the best weapon for a logistic and industrial reason, but IMO it's only a matter of relative usage. It was enough for them because of other factors: it was the better weapon for THEM.

But just switch all the German cannons with Browning on the Luftwaffe planes and the war is going to end 2 years beforehand.

Edited December 16, 2013 by 6S.Manu

[DD_fruitbat]

I agree with Manu.

 

Every other airforce moved to 20mm's early to mid war, the US navy was already moving to 20mms by the end of the war, it just took the USAAF untill after the war to change.

 

 

 

I agree that it's the best weapon for a logistic and industrial reason

 

This amongst all else was the USAAF reasons for prolonged use of 50's.

 

I'm not saying that 50's wasn't an effective weapon system against fighters, as it was otherwise the change would of been much sooner, but it also wasn't as good as 20mm's, no matter how much people want to believe in the myth.

Edited December 16, 2013 by fruitbat

[Sternjaeger]

I disagree with every point you made except the #4.

 

If .50 cals were so better can you explain to my why the US warbird were the sole to use an HMG as main weapon?

The RAF could mount that but they stayed with the Hispanos. The Russians could copy them but they didn't.

 

I agree that it's the best weapon for a logistic and industrial reason, but IMO it's only a matter of relative usage. It was enough for them because of other factors: it was the better weapon for THEM.

But just switch all the German cannons with Browning on the Luftwaffe planes and the war is going to end 2 years beforehand.

 

1) because standardisation wins wars

2) because they found the perfect, most versatile, most reliable, most easy to maintain and repair HMG of the war. 

 

Americans also used the Hispano Suiza cannon, but the open bolt design proved to be a dangerous problem and pilots lacked confidence in the gun.

 

It is not a case that until a better 20mm was introduced, the USAF kept on using the 50 cal (think of the F-86 and all the 50s jets). 

 

I'm not saying that cannons were bad guns, but you can't logically deny all the points I've made, or at least you'll have to explain why. 

 

By 1945 the Luftwaffe had at least 12 different calibres in use (and for each calibre they had a lot of variations), the americans 5 (of which only 3 were of widespread use).

I'm not saying that 50's wasn't an effective weapon system against fighters, as it was otherwise the change would of been much sooner, but it also wasn't as good as 20mm's, no matter how much people want to believe in the myth.

 

what do you mean exactly when you say "it wasn't as good as 20mm"? Good at what? And how? 

Edited December 16, 2013 by Sternjaeger

[216th_Jordan]

I agree with Stern, and it depends a lot on the purpose of the Weapons system. Luftwaffe would not have been able to make use of the BMG because its goal was not to shoot down other fighters primarily but to bring down heavy, big and slow bombers. The USAAFs main goal was to protect the bombers and to attack fighterplanes. This makes a hell of a difference, and it's just one factor.

[Finkeren]

I agree with Stern, and it depends a lot on the purpose of the Weapons system. Luftwaffe would not have been able to make use of the BMG because its goal was not to shoot down other fighters primarily but to bring down heavy, big and slow bombers. The USAAFs main goal was to protect the bombers and to attack fighterplanes. This makes a hell of a difference, and it's just one factor.

That's an extreme oversimplification.

 

First: No, Luftwaffe single seat fighters were generally not designed with the purpose of bringing down heavy bombers, though they did adopt increasingly heavy weapons for that purpose.

 

With the posible exception of the P-51, almost every single engined fighter in WW2 started out as an air superiority fighter and were later adopted into other roles, including some they were ill suited for.

 

Likewise the USAAF fighters in general weren't specifically designed for escort duties, but were adopted for that as necessity arose.

[6S.Manu]

1) because standardisation wins wars

2) because they found the perfect, most versatile, most reliable, most easy to maintain and repair HMG of the war. 

 

Americans also used the Hispano Suiza cannon, but the open bolt design proved to be a dangerous problem and pilots lacked confidence in the gun.

 

It is not a case that until a better 20mm was introduced, the USAF kept on using the 50 cal (think of the F-86 and all the 50s jets). 

 

I'm not saying that cannons were bad guns, but you can't logically deny all the points I've made, or at least you'll have to explain why. 

 

By 1945 the Luftwaffe had at least 12 different calibres in use (and for each calibre they had a lot of variations), the americans 5 (of which only 3 were of widespread use).

 

what do you mean exactly when you say "it wasn't as good as 20mm"? Good at what? And how? 

 

1) Standardization is only one of the factors in winning a war: military tactics, research skill, manpower and raw material availability are others... IMO these are far more important than equipment standardization.

 

The main German fighter was all about that. It was ready for mass production and designed to be easily maintainable on the field. But still...

 

2) It must be luck then... as twenty years after they couldn't develop an infantry rifle with the same qualities. :-D

Anyway you didn't answer to my question about RAF and the Russians.

 

They tried to product a reliable Hispano cannon for them and the British (to transfer the production oversea), but the result was very disappointing: still the British could make it work right. The US continued fix the problem until Late 1945!

 

As fruitbat says, the U.S. Navy wanted to use cannons in their planes... they couldn't since the American cannon wasn't reliable, not because of a planned weapon standardization.

 

12 different calibers? I count 5 of them... 8 with the anti tank cannons... you know, then you have to fight a war against armored vehicles you need bigger guns... can you imagine the P47s strafing hundreds of T-34 in Kursk? The British were dumb too in using 40mm cannons in Africa. it's good for the US to have fight against the weak Japanese airforce in the PTO since they were really late with equipment.

 

Then your points:

1) With weapon based on kinetic energy damage you need to be close to the target: it's not about hitting the enemy, it's about damage him. The best effective range is 200m, but if you want to fire farther you need a pattern harmonization or firing result too difficult having wing mounted weapons. A good pilot could use a point harmonization but then he need to stay at the right distance to do real damage. And that right distance must still be short.

Now try to take down bombers with that configuration (no, I'm not talking about "the one-shot lighter" Betties ). With cannons you can fire at longer distance, staying out of the defensive turrets range, and still be effective since cannons base their damage on explosive. 

I will ignore the part about cannons be difficult if used in deflection shooting... the Germans have never taken down anything; I don't think the real reason was their LMGs...

 

2) There are no many accounts of pilots firing everything they had... most of the time they were firing only when they were able to... This is about fighter vs fighter. Instead if we talk bomber hunting and strafing missions, then I agree that the more ammo the better: unfortunately explosive shells do more damage to both bombers and ground vehicles (the latter is one of the reasons Typhoon and Tempest retain the Hispanos... IMO).

 

3) Probably there were fighters RTB with unexploded shells on them... why don't we talk about the ones who didn't returned back after only 3 shells? I'm quite sure there are many more fighters RTB with HMG holes in them...

 

4) I agree.

 

5) A lot? IMO the most dangerous parts are still the fuel tanks and the explosion of the ammo were still a rare accident (above all because of API rounds, while I can understand it they were hit by HE rounds). Then we talk about pilots unmounting the wing cannons on the FW190 could be that because the armament was heavy and it was really reducing the performance of the plane? But I guess it was since they were afraid of explode in air: they were fighting a war and they were afraid to die, of course... or maybe the Pros of having wing mounted cannons were not enough (heavier plane and slower roll rate)? (see the 109 versions after the Emil didn't mount wing cannons, not the Fw190 Dora, not the Ta series).

 

6) It's related to the point #2. Heavy shells mean less shells... Which is the right number? Does the mission need ammo quality or quantity? If you're going in a head on against a B17 I think you would some dozen of mk108's shells, not 1880 .50 cal slugs.

 

 

Edited December 16, 2013 by 6S.Manu

[FuriousMeow]

This is quite clearly becoming less an argument of HMG vs Cannon and more which side (Axis vs Allies - actually more accurately Germany vs Allies) did it right.

 

The misstep was the P51 in the title, it always brings in the pony haters and the Luftwaffle lovers.

Edited December 16, 2013 by FuriousMeow

[6S.Manu]

This is quite clearly becoming less an argument of HMG vs Cannon and more which side (Axis vs Allies - actually more accurately Germany vs Allies) did it right.

 

The misstep was the P51 in the title, it always brings in the pony haters and the Luftwaffle lovers.

 

Nope.

 

It's more:

A: Browning M2s are the best

B: Maybe, lets talk about that

A: No, it's true and they're better than cannons too!

B: ...

 

It's not about Axis vs Allies at all. 

Edited December 16, 2013 by 6S.Manu

[Sternjaeger]

1) Standardization is only one of the factors in winning a war: military tactics, research skill, manpower and raw material availability are others... IMO these are far more important than equipment standardization.

The main German fighter was all about that. It was ready for mass production and designed to be easily maintainable on the field. But still...

 

Exactly, I think the best definition for Luftwaffe armament was "deluded". Even the basic HMG, the MG131, was a very complicated round to produce and required a lot of different materials. Over-engineering is what really damaged the Luftwaffe and the other armed forces of Nazi Germany.

 

2) It must be luck then... as twenty years after they couldn't develop an infantry rifle with the same qualities. :-D

Anyway you didn't answer to my question about RAF and the Russians.

 

Maybe, but it still remains that they found a suitable calibre and gun and improved it throughout the war (and afterwards). A design so solid that is still used throughout the world nowadays.

Both the Russian and British introduced cannons after they saw them in action against them from the Germans, thinking that they were the real game changer in aerial warfare, even if soon they found out that it wasn't the case. The Brits adopted the .50 cal for the Spitfires as soon as they realised how good they were together with the Hispano cannons, and the Russians went on trying all sorts of calibres, being convinced (in typical Russian fashion) that "the bigger the better", but then proved to be only good for ground attacks. 

As for the rifles, you might have heard of the M-1 Garand, M-14 and M-16, I think they pretty much cover almost a century of semiauto guns..

 

They tried to product a reliable Hispano cannon for them and the British (to transfer the production oversea), but the result was very disappointing: still the British could make it work right. The US continued fix the problem until Late 1945!

 

As fruitbat says, the U.S. Navy wanted to use cannons in their planes... they couldn't since the American cannon wasn't reliable, not because of a planned weapon standardization.

 

Obviously you are not fully aware of the development history of the Hispano-Suiza: read more about it here http://en.wikipedia.org/wiki/Hispano-Suiza_HS.404

 

12 different calibers? I count 5 of them... 8 with the anti tank cannons... you know, then you have to fight a war against armored vehicles you need bigger guns... can you imagine the P47s strafing hundreds of T-34 in Kursk? The British were dumb too in using 40mm cannons in Africa. it's good for the US to have fight against the weak Japanese airforce in the PTO since they were really late with equipment.

 

Count better: MG17, MG131, MG151/15, MGFF, MG151/20, MG204, MK108, MK101, MK103, BK37, BK5, BK75 (and I'm not even mentioning the countless prototypes, sub variants etc…)

 

US: .30 cal, .50 cal, 20x110mm, 37mm, 75mm

 

Americans wouldn't have used guns, they would have used the much more efficient high velocity rockets they had available.  The 40mm Vickers S wasn't dumb at all, unless you think the Stuka's 37mm was.. 

 

And for the record, a lot of the Japanese ammunition was copied from German one. 

 

Then your points:

1) With weapon based on kinetic energy damage you need to be close to the target: it's not about hitting the enemy, it's about damage him. The best effective range is 200m, but if you want to fire farther you need a pattern harmonization or firing result too difficult having wing mounted weapons. A good pilot could use a point harmonization but then he need to stay at the right distance to do real damage. And that right distance must still be short.

Now try to take down bombers with that configuration (no, I'm not talking about "the one-shot lighter" Betties ). With cannons you can fire at longer distance, staying out of the defensive turrets range, and still be effective since cannons base their damage on explosive. 

I will ignore the part about cannons be difficult if used in deflection shooting... the Germans have never taken down anything; I don't think the real reason was their LMGs...

 

Harmonisation could be one on different patterns: Hofer used to fly with each couple of guns (two outer, two middle, two inner) harmonised in couples, so that he could still have a good firing solution at different distances. Practice makes perfection, and the introduction of gyro gunsights made things even easier. Note how the original K-14 design principle has remained in service with different air forces up until the early 70s. 

You CAN'T fire from long distances with cannons, simply because they don't have the same excellent ballistic properties of HMG rounds. The Germans boomed and zoomed at very steep angles to compensate for the poor ballistics and to offer less of a target whilst getting as close as possible. 50 cals of defensive turrets had a further effective range of German cannons, especially when time-fuzed rounds were used.

 

2) There are no many accounts of pilots firing everything they had... most of the time they were firing only when they were able to... This is about fighter vs fighter. Instead if we talk bomber hunting and strafing missions, then I agree that the more ammo the better: unfortunately explosive shells do more damage to both bombers and ground vehicles (the latter is one of the reasons Typhoon and Tempest retain the Hispanos... IMO).

 

They were just aiming at the wrong spots: the experten learned the lesson quick - you want to shoot down a bomber, you destroy its cockpit. No need to damage engines, wings, tails etc...

 

3) Probably there were fighters RTB with unexploded shells on them... why don't we talk about the ones who didn't returned back after only 3 shells? I'm quite sure there are many more fighters RTB with HMG holes in them...

 

We're talking about efficiency and reliability here.

 

4) I agree.

 

5) A lot? IMO the most dangerous parts are still the fuel tanks and the explosion of the ammo were still a rare accident (above all because of API rounds, while I can understand it they were hit by HE rounds). Then we talk about pilots unmounting the wing cannons on the FW190 could be that because the armament was heavy and it was really reducing the performance of the plane? But I guess it was since they were afraid of explode in air: they were fighting a war and they were afraid to die, of course... or maybe the Pros of having wing mounted cannons were not enough (heavier plane and slower roll rate)? (see the 109 versions after the Emil didn't mount wing cannons, not the Fw190 Dora, not the Ta series).

 

You probably don't have a lot of experience with firearms: an API round is a REALLY REALLY effective kind of ammunition. So much so that it's the primary round used nowadays as well.

 

6) It's related to the point #2. Heavy shells mean less shells... Which is the right number? Does the mission need ammo quality or quantity? If you're going in a head on against a B17 I think you would some dozen of mk108's shells, not 1880 .50 cal slugs.

 

Every pilot will tell you he'll be happy with more ammo, especially when it's a gun with great ballistic performance, that can allow you to be precise at a further distance.

 

and yes, this conversation has been very civilised so far, don't see where the problem is? 

[ImPeRaToR]

This is quite clearly becoming less an argument of HMG vs Cannon and more which side (Axis vs Allies - actually more accurately Germany vs Allies) did it right.

 

The misstep was the P51 in the title, it always brings in the pony haters and the Luftwaffle lovers.

I disagree, Manu did mentioned the British and even the Hurricane with the 40mm guns so it is actually about cannons vs HMG.

 

Now, since we already established that the Berezin was fairly close to the M2 in performance and actually quite a bit lighter, why did the Russians decide to keep using the SHVAK cannon, even several in one plane (La series), or even bigger guns (23 and 37mm), or even develop a cannon based on the UB (the B20, three of them in La7s built in 45) if heavy machine guns are so awesome? And they didn't even meet that many bombers let alone heavy bombers like the B17 or B24, plus the main German "bomber" of 44 and 45 was the Fw90F. So the urgency for bomber interception is no valid reason at all, nor is it a valid reason for the 109F and early G.

 

 

The Brits adopted the .50 cal for the Spitfires as soon as they realised how good they were together with the Hispano cannons

They did it because .30 cal were shit and the bigger the better

 

 

being convinced (in typical Russian fashion) that "the bigger the better", but then proved to be only good for ground attacks.

Also questionable, P-39 and Yak9T were used extensively and probably close to exclusviely against German aircraft, much to the enjoyment of the Russian pilots. If you haven't noticed, many Russian aces scored the majority of their kills on the P-39.

 

 

Now you mention the M16, I think that's exactly the point Manu was trying to make. But that's entirely offtopic and too emotional for this forum I think

Edited December 16, 2013 by ImPeRaToR

[79_vRAF_Friendly_flyer]

According to the US Bureau of Ordnance, Department of the Navy (Chinn 1951), the US was trying to switch over to cannons from 1942 and onwards, but were held back by manufacturing problems with the US version of the Hispano. The problem was resolved with the introduction of electric primers, in time for the US to switch during the Korean war.

 

For the gun-nerds:

 

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

 

Having said that, what constitute a "great gun" depends on whet you need to shoot at. The situation the US met over Europe and in the Pacific allowed the M2 to be a great gun. As the title states, the Mustang with its battery of HMGs would probably be a very competitive fighter in this sim, at least as long as the possible opponents are the 109 and LaGG. The battery of HMGs are well suited to shooting at fast maneouvering fighters.

Edited December 16, 2013 by 79_vRAF_Friendly_flyer

[Sternjaeger]

I disagree, Manu did mentioned the British and even the Hurricane with the 40mm guns so it is actually about cannons vs HMG.

 

Now, since we already established that the Berezin was fairly close to the M2 in performance and actually quite a bit lighter, why did the Russians decide to keep using the SHVAK cannon, even several in one plane (La series), or even bigger guns (23 and 37mm), or even develop a cannon based on the UB (the B20, three of them in La7s built in 45) if heavy machine guns are so awesome? And they didn't even meet that many bombers let alone heavy bombers like the B17 or B24, plus the main German "bomber" of 44 and 45 was the Fw90F. So the urgency for bomber interception is no valid reason at all, nor is it a valid reason for the 109F and early G.

 

I think the Russians were actually disappointed with the reliability and effectiveness of the UB and ShKas, that's why they concentrated on larger calibres. The principle was that as long as you could place one powerful round on the enemy, you'd be a winner. It's a different approach to gunnery which didn't need high skills, but just following basic rules. 

This debate will carry on during the Korean conflict as well: the confrontation between the two "shooting philosophies" will become even clearer in the F-86 vs. Mig-15 dogfights. 

 

They did it because .30 cal were shit and the bigger the better

they just realised the .303 was not effective anymore (and perhaps had never really been).

 

Also questionable, P-39 and Yak9T were used extensively and probably close to exclusviely against German aircraft, much to the enjoyment of the Russian pilots. If you haven't noticed, many Russian aces scored the majority of their kills on the P-39.

 

Same as above, different philosophy: the Russian pilots removed the wing guns on the P-39s and relied mainly on the big cannon, but with only 30 rounds they complained about the limited firepower.

 

Now you mention the M16, I think that's exactly the point Manu was trying to make. But that's entirely offtopic and too emotional for this forum I think

 

The M-16 platform is an extremely good and versatile one, it's a well built and truly customisable one, but you know, haters gonna hate  

I personally prefer the AK-47, but then again it really depends what you need to use your toy for..

[DD_fruitbat]

Both the Russian and British introduced cannons after they saw them in action against them from the Germans, thinking that they were the real game changer in aerial warfare, even if soon they found out that it wasn't the case. The Brits adopted the .50 cal for the Spitfires as soon as they realised how good they were together with the Hispano cannons

 

The 50 cal was the secondary weapon system after the Hispano in the 'e wing' used by the British. It replaced the much worse 303 secondary weapon system, found in the b an c wing.

 

If the British and Russians had really thought that 20mm's were overrated they would of changed to all 50 cal. They did not however.

[Sternjaeger]

Guys, I don't think the Americans thought the 20mm were overrated, they just wanted to use a gun platform solution that proved to be flexible and dependable. 

 

The training for deflection shooting was a very important part of pilots' syllabus, it was just a different approach to gunnery. Don't forget that this allowed them to hit their targets at further distances than the opponents would normally would open fire at, giving them a much larger number of shooting solutions and a slight edge, especially with the introduction of gyro gunsights.

Edited December 17, 2013 by Sternjaeger

[-MG-Cacti4-6]

Guys, I don't think the Americans thought the 20mm were overrated, they just wanted to use a gun platform solution that proved to be flexible and dependable. 

 

The training for deflection shooting was a very important part of pilots' syllabus, it was just a different approach to gunnery. Don't forget that this allowed them to hit their targets at further distances than the opponents would normally would open fire at, giving them a much larger number of shooting solutions and a slight edge, especially with the introduction of gyro gunsights.

this!

 

its not a slight against the 20mm, there were multiple reasons why the US chose using an absurd amount of 50cals. but this one here was at or near the top of the list

[dkoor]

I wont get down into history business (much) or talk about technical side of this story.

 

I think that you guys are all basically saying the same story when put into the perspective.

 

Some airplanes had fewer cannons, some had more HMG's... the result was probably roughly the same.

I don't think I could be talked out of thinking that P-51D armament value wasn't as good as some other airplane armed with two 20mms.

Say La-5 or 7. Maybe only for some extra exotic strafing missions where 20mm armour piercing could do some stuff to armour that 12,7 could not.

 

I'll step a bit further here...

I also think we may need to take into account that airplane design "asked" for armament type.

For instance I don't think you could ducktape six Brownings on Me-109's wings, at least not if you want it to perform flying better than Boeing 747.

I don't see those installed successfully on La's or Yak's.

 

Furthermore, those stories of Americans being unable to produce reliable 20mms seem to be among the finest fairy tales I ever heard.

I mean we are talking about guys who produced P-38, P-47, P-51 which were fast great at hi-alts and had two or three times range of average ww2 fighter, B-29 hi-alt fast bomber when others struggled to catch it with fighters, supplied the British and Soviets with equipment of war  and ofc... atomic bomb.

 

Buuuut... they could not shell out decent 20mm aircraft cannon by the time everyone and their mothers had some rather usable variant of those.

Even so, was it so hard to ask the British what was the secret 20mm formula? Maybe they were too selfish, who knows...

 

You guys seriously buy this?

Edited December 17, 2013 by dkoor

[Sternjaeger]

We don't have to buy anything, it's history proven by documents.

 

The development of a gun is a very demanding process, and I think that as they proceeded they realised they didn't really need them that much, as the guns they had on all their aircraft had proven effective as they where, so why re-invent the wheel?

 

In reality the "need" for development of a dependable 20mm cannon was also due to the fact that the US invested in the production of some 10million 20mm rounds and really needed to find use for them!

 

The misconception I often meet is that "20mm is better than 50 cal", which is really comparing apples and pears, and is often wrong. You need to put an armament into context to measure its effectiveness, and the 50 cal proved to be capable to perfectly do its job both for air superiority and for ground attacks, at a fraction of the cost and more efficiently than 20mm rounds.

Edited December 17, 2013 by Sternjaeger

[SOLIDKREATE]

I hope they release a Battle of the Bulge campaign at the end of next year. That way we can have the P-51D-15-NA, La-7B, P-63 and the Bf-109G-10 and Fw-190D-9 & F-8.

[-MG-Cacti4-6]

I hope they release a Battle of the Bulge campaign at the end of next year. That way we can have the P-51D-15-NA, La-7B, P-63 and the Bf-109G-10 and Fw-190D-9 & F-8.

only if the p51's and p47's that will be there (as well as the p38's i would assume...giggity) handle properly. that other game....you know the one....yeah....

[79_vRAF_Friendly_flyer]

I also think we may need to take into account that airplane design "asked" for armament type.

For instance I don't think you could ducktape six Brownings on Me-109's wings, at least not if you want it to perform flying better than Boeing 747.

 

...

 

Furthermore, those stories of Americans being unable to produce reliable 20mms seem to be among the finest fairy tales I ever heard.

I mean we are talking about guys who produced P-38, P-47, P-51 which were fast great at hi-alts and had two or three times range of average ww2 fighter, B-29 hi-alt fast bomber when others struggled to catch it with fighters, supplied the British and Soviets with equipment of war  and ofc... atomic bomb.

 

...

 

Even so, was it so hard to ask the British what was the secret 20mm formula? Maybe they were too selfish, who knows...

 

You guys seriously buy this?

 

Good point about what type of armament a plane can take. The philosophy behind the Mustang and the Thunderbolt was quite different from that behind the British, German and Japanese fighters. The American planes were large and powerful, the fighters of other nations were built to be small and light. If you put a Thunderbolt next to a Spitfire, it is fairly obvious that there's no way the British machine would fly well with the same armament. Actually, it was even difficult for the Spitfire to accommodate the 8 .303 Brownings, they had to be spread all along the wings.

 

I did not believe the story of the borked US Hispano the first time I heard it either, but it seem to be the case. I really suggest you take the time to read Chinn's book, link here: http://ibiblio.org/hyperwar/USN/ref/MG/I/MG-5.html#birkigt scroll down to page 570 and read on (20 pages), it is a fascinating, if extremely frustrating read.

 

To make a long story short: The US started off in 1938 with an early pre-production British gun, which did not work too well. The Americans tried to improve the design, and in the process made the chamber one-sixteenth inch (about 4,2 mm) deeper than the British gun. This lead to the striker not always striking the primer appropriately, leading to frequent stoppage. As war broke out and progressed, calls for standardization with the British Hispano prevented the US from making longer cartridges, and with the ammunition manufacturers, gun designers, the Board of Artillery and Board of Ordnance all proposing different solutions while blaming each other, the error was never corrected.

 

The British did on a number of occasions offer advice, send drawings for their improved guns (the Mk. II and V) and very politely suggested shortening the chamber a bit, but non of it helped it seems. The USN, who needed the guns the most (when faced with Kamikaze pilots or a torpedo bomber heading for your ship, HMGs simply won't do) opted to install the gun anyway, even a faulty 20 mm was better than HMGs. This is probably where the reputation for unreliability Sternjaeger mentioned comes from.

 

After the war, the problem with the striker was solved by switching to electrical primers.

Edited December 17, 2013 by 79_vRAF_Friendly_flyer

[79_vRAF_Friendly_flyer]

We don't have to buy anything, it's history proven by documents.

 

Here's Chinn's conclusion about the development of the American Hispano:

 

Nothing was basically wrong with the weapon. Its wartime performance, good or bad, was the result of having been bought in desperation, put into mass production without first having been adequately proved, and then modified regularly to meet a future commitment before the previous model had been made to function reliably.

[6S.Manu]

1) Standardization is only one of the factors in winning a war: military tactics, research skill, manpower and raw material availability are others... IMO these are far more important than equipment standardization.

The main German fighter was all about that. It was ready for mass production and designed to be easily maintainable on the field. But still...

 

Exactly, I think the best definition for Luftwaffe armament was "deluded". Even the basic HMG, the MG131, was a very complicated round to produce and required a lot of different materials. Over-engineering is what really damaged the Luftwaffe and the other armed forces of Nazi Germany.

Still I think that standardization and over-engineering are not the main reasons of their defeat.

 

2) It must be luck then... as twenty years after they couldn't develop an infantry rifle with the same qualities. :-D

Anyway you didn't answer to my question about RAF and the Russians.

 

Maybe, but it still remains that they found a suitable calibre and gun and improved it throughout the war (and afterwards). A design so solid that is still used throughout the world nowadays.

Both the Russian and British introduced cannons after they saw them in action against them from the Germans, thinking that they were the real game changer in aerial warfare, even if soon they found out that it wasn't the case. The Brits adopted the .50 cal for the Spitfires as soon as they realised how good they were together with the Hispano cannons, and the Russians went on trying all sorts of calibres, being convinced (in typical Russian fashion) that "the bigger the better", but then proved to be only good for ground attacks. 

As for the rifles, you might have heard of the M-1 Garand, M-14 and M-16, I think they pretty much cover almost a century of semiauto guns..

The prototype of the P-39 in mid 1938 featured a cannon. The French mounted a cannon in their Morane-Saulnier M.S.406, in mid 1935 (that gave the idea to the Germans for the central cannon). 

 

"In fact, the RAF had realised years before the war that the .303 MG might become inadequate as a primary aircraft gun, given the steady increase in speed, strength and toughness of aircraft. They considered, but rejected, .50 inch (12.7 mm) guns as giving insufficient advantage over the .303. Instead, they sought a good 20 mm cannon, which they thought would be far more effective due to its explosive ammunition, and found one in the new French Hispano-Suiza HS.404. This was selected in the late 1930s, and specifications were written for a new fighter to carry it (the Westland Whirlwind), but problems in setting up UK factories meant that only a few guns were available at the time of the Battle of Britain.

 

The HS.404 was designed and developed at the French arm of Hispano-Suiza company in the mid 1930s. A firing demonstration of a prototype to British officers in Paris in 1936 banished all thought of the Oerlikon; the Hispano was similar in size and weight, slightly more powerful and fired nearly twice as fast. Unfortunately, the processes of obtaining approval to buy the gun, setting up a subsidiary Hispano factory at Grantham (the British Manufacturing And Research Company, or BMARCO), redrawing the gun to imperial rather than metric units, testing and debugging the prototypes, then fitting them into aircraft and debugging the installations, all took too long for the cannon to achieve anything before the war."

 

Yep, I was talking about th M-16 and his reliability compared to the AK47.

 

They tried to product a reliable Hispano cannon for them and the British (to transfer the production oversea), but the result was very disappointing: still the British could make it work right. The US continued fix the problem until Late 1945!

 

As fruitbat says, the U.S. Navy wanted to use cannons in their planes... they couldn't since the American cannon wasn't reliable, not because of a planned weapon standardization.

 

Obviously you are not fully aware of the development history of the Hispano-Suiza: read more about it here http://en.wikipedia....no-Suiza_HS.404

I know history, thanks. 

 

So, why was the U.S. Navy trying to mount full-cannons on their planes?

 

12 different calibers? I count 5 of them... 8 with the anti tank cannons... you know, then you have to fight a war against armored vehicles you need bigger guns... can you imagine the P47s strafing hundreds of T-34 in Kursk? The British were dumb too in using 40mm cannons in Africa. it's good for the US to have fight against the weak Japanese airforce in the PTO since they were really late with equipment.

 

Count better: MG17, MG131, MG151/15, MGFF, MG151/20, MG204, MK108, MK101, MK103, BK37, BK5, BK75 (and I'm not even mentioning the countless prototypes, sub variants etc…)

 

US: .30 cal, .50 cal, 20x110mm, 37mm, 75mm

 

Americans wouldn't have used guns, they would have used the much more efficient high velocity rockets they had available.  The 40mm Vickers S wasn't dumb at all, unless you think the Stuka's 37mm was.. 

 

And for the record, a lot of the Japanese ammunition was copied from German one. 

You mean cartridges, not calibers. 

 

PS: The "dumb" thing was sarcasm. They had to fight against tanks... They need big guns.

 

Then your points:

1) With weapon based on kinetic energy damage you need to be close to the target: it's not about hitting the enemy, it's about damage him. The best effective range is 200m, but if you want to fire farther you need a pattern harmonization or firing result too difficult having wing mounted weapons. A good pilot could use a point harmonization but then he need to stay at the right distance to do real damage. And that right distance must still be short.

Now try to take down bombers with that configuration (no, I'm not talking about "the one-shot lighter" Betties ). With cannons you can fire at longer distance, staying out of the defensive turrets range, and still be effective since cannons base their damage on explosive. 

I will ignore the part about cannons be difficult if used in deflection shooting... the Germans have never taken down anything; I don't think the real reason was their LMGs...

 

Harmonisation could be one on different patterns: Hofer used to fly with each couple of guns (two outer, two middle, two inner) harmonised in couples, so that he could still have a good firing solution at different distances. Practice makes perfection, and the introduction of gyro gunsights made things even easier. Note how the original K-14 design principle has remained in service with different air forces up until the early 70s. 

You CAN'T fire from long distances with cannons, simply because they don't have the same excellent ballistic properties of HMG rounds. The Germans boomed and zoomed at very steep angles to compensate for the poor ballistics and to offer less of a target whilst getting as close as possible. 50 cals of defensive turrets had a further effective range of German cannons, especially when time-fuzed rounds were used.

 

You aren't going to fire at long range with HMG both for the loss of kinetik power and the wing mounted. Of course the bullets have a flatter trajectory: that's the main advantage. But if you are not firing at the right convergence then most of the bullet are going to miss the target.

 

The cannons CAN fire at long range... The higher point in the parabolic arc made by a MG 151/20 set with convergence of for firing at 600m was of about 1 meter above the line of sight. Only a 1 Meter. 

 

Gyro gunsights are really useful against leveled planes: they are less good for deflection shooting... there it's all instinct (and firing IS mainly instinct). BTW they are useful to HMG as to cannons...

 

2) There are no many accounts of pilots firing everything they had... most of the time they were firing only when they were able to... This is about fighter vs fighter. Instead if we talk bomber hunting and strafing missions, then I agree that the more ammo the better: unfortunately explosive shells do more damage to both bombers and ground vehicles (the latter is one of the reasons Typhoon and Tempest retain the Hispanos... IMO).

 

They were just aiming at the wrong spots: the experten learned the lesson quick - you want to shoot down a bomber, you destroy its cockpit. No need to damage engines, wings, tails etc...

Not quick enough, if they tried to take them down with bombs. How many head on attacks they are going to make in your opinion? 1) it's not a easy tactic (you need to be aligned with the bomber stream). 2) you have few firing seconds. 3) Once you made your attack you have to recatch the stream... while the escort is there for you.

 

Firing everything you had trying to damage the bomber could be the better tactic for average pilots. In that case the more ammo is better; if the guy is a good shot, when few shells of high caliber cannon are enough.

 

 

3) Probably there were fighters RTB with unexploded shells on them... why don't we talk about the ones who didn't returned back after only 3 shells? I'm quite sure there are many more fighters RTB with HMG holes in them...

 

We're talking about efficiency and reliability here.

If you talk about efficiency surely you know the % of defective shells. Cannons are also more prone to jamming: still the Germans used the mk108. Maybe since it was need one shot to make the difference?

 

5) A lot? IMO the most dangerous parts are still the fuel tanks and the explosion of the ammo were still a rare accident (above all because of API rounds, while I can understand it they were hit by HE rounds). Then we talk about pilots unmounting the wing cannons on the FW190 could be that because the armament was heavy and it was really reducing the performance of the plane? But I guess it was since they were afraid of explode in air: they were fighting a war and they were afraid to die, of course... or maybe the Pros of having wing mounted cannons were not enough (heavier plane and slower roll rate)? (see the 109 versions after the Emil didn't mount wing cannons, not the Fw190 Dora, not the Ta series).

 

You probably don't have a lot of experience with firearms: an API round is a REALLY REALLY effective kind of ammunition. So much so that it's the primary round used nowadays as well.

I don't want to enter in this in this discussion: IMO the probability of HE ammo's explosion by API hits was really-really low. IIRC there are not documents about this issue. 

 

6) It's related to the point #2. Heavy shells mean less shells... Which is the right number? Does the mission need ammo quality or quantity? If you're going in a head on against a B17 I think you would some dozen of mk108's shells, not 1880 .50 cal slugs.

 

Every pilot will tell you he'll be happy with more ammo, especially when it's a gun with great ballistic performance, that can allow you to be precise at a further distance.

Did you speak with every WW2 pilot out there? It's not about what the pilots want: it's about what it's more efficient for the purpose. Quality vs quantity.

Edited December 17, 2013 by 6S.Manu

[Sternjaeger]

yep, bought in a hurry, not fully tested, failed. 

 

The British had a lot of problems with the Hispano Suiza anyway: the gun was prone to freezing, and an adequate and reliable heating system was introduced only after 1943. 

 

The electrical primer and the redesign of the case done for the US Navy made the difference in the later development of the Hispano Suiza, and the gun became standard for many years on their aircraft.

[6S.Manu]

I also think we may need to take into account that airplane design "asked" for armament type.

For instance I don't think you could ducktape six Brownings on Me-109's wings, at least not if you want it to perform flying better than Boeing 747.

I don't see those installed successfully on La's or Yak's.

 

Of course!

 

Tony Williams says it on his article (http://www.quarry.nildram.co.uk/CannonMGs.htm)

 

To return to the original question, were the Americans right to rely so heavily on the .50 M2 when all other combatant nations had a clear preference for cannon of at least 20 mm calibre? The answer has to be yes. It was adequate for its purpose, and was the only satisfactory aircraft gun in production in the USA. It was very reliable (except where the installations created problems), was made in huge quantities, and the simplification of supply by comparison with the diversity of weapons used by the Axis powers gave a major logistical advantage. However, the Americans could get away with using a weapon so deficient in destructive power not only because of the nature of their opposition, but also because the size and engine power of their fighters enabled them to carry a battery of at least six guns, thus making up in quantity what they lacked in destructive quality.

Edited December 17, 2013 by 6S.Manu

[Sternjaeger]

Still I think that standardization and over-engineering are not the main reasons of their defeat.

 

Well, that's your opinion, which I respect, but which unfortunately is confuted by a lot of historians and by empirical evidence. 

 

The prototype of the P-39 in mid 1938 featured a cannon. The French mounted a cannon in their Morane-Saulnier M.S.406, in mid 1935 (that gave the idea to the Germans for the central cannon). 

 

So? I don't get the point? 

"In fact, the RAF had realised years before the war that the .303 MG might become inadequate as a primary aircraft gun, given the steady increase in speed, strength and toughness of aircraft. They considered, but rejected, .50 inch (12.7 mm) guns as giving insufficient advantage over the .303. Instead, they sought a good 20 mm cannon, which they thought would be far more effective due to its explosive ammunition, and found one in the new French Hispano-Suiza HS.404. This was selected in the late 1930s, and specifications were written for a new fighter to carry it (the Westland Whirlwind), but problems in setting up UK factories meant that only a few guns were available at the time of the Battle of Britain.

 

The HS.404 was designed and developed at the French arm of Hispano-Suiza company in the mid 1930s. A firing demonstration of a prototype to British officers in Paris in 1936 banished all thought of the Oerlikon; the Hispano was similar in size and weight, slightly more powerful and fired nearly twice as fast. Unfortunately, the processes of obtaining approval to buy the gun, setting up a subsidiary Hispano factory at Grantham (the British Manufacturing And Research Company, or BMARCO), redrawing the gun to imperial rather than metric units, testing and debugging the prototypes, then fitting them into aircraft and debugging the installations, all took too long for the cannon to achieve anything before the war."

 

Yes, this is a typical example of wrong guns applied to aircraft design: the RAF made a lot of mistakes throughout the war, and this is a typical example of it. Thinking of using a single HMG in place of a cannon is obviously not going to give you the desired results, it's a matter of right combination of aircraft design and adequate weapon for it. Those were the days where the "Dowding spread" was still considered the winning formula, and by the end of the Battle of Britain experience they'd learn the importance of gun convergence above all. It's not a coincidence that subsequently the RAF ditched the .303s in favour of the .50 cal. 

 

Yep, I was talking about th M-16 and his reliability compared to the AK47.

 

An M-16 is a perfectly reliable gun if maintained adequately. The fact that the AK needs little or no maintenance doesn't make it a better gun. The ammo is heavier, the ballistics are inferior and so is accuracy at long distance, once again it's a classic example of the right gun for the job.

I know history, thanks. 

 

It doesn't seem you know history of cannon development, or at least didn't read about it.

 

So, why was the U.S. Navy trying to mount full-cannons on their planes?

 

They tried because they wanted to use effective HE ammunition on ground attacks, but they never fully got there in WW2. They never had a gun that proved good enough for the job, that's why even in the Navy the 20mm Hispano Suiza saw very little service. 

The USAAF fighters were concentrated on aerial superiority at first, but even when they were needed as ground pounders, they slapped in an extra MG, rocket and bomb racks, and the P-47s did their job superbly.  That's a versatile solution.

 

You mean cartridges, not calibers. 

 

No, those were only the calibres, the variation of cartridges within those calibres probably reached the 55/60 types of different rounds. A bit too much, don't you think? Thing about all the machinery, materials, workmanship and time needed to produce such a wide variety of ammunition.

 

PS: The "dumb" thing was sarcasm. They had to fight against tanks... They need big guns.

 

No, they needed rockets, as they learned themselves with the Typhoons in Normandy.

 

 

You aren't going to fire at long range with HMG both for the loss of kinetik power and the wing mounted. Of course the bullets have a flatter trajectory: that's the main advantage. But if you are not firing at the right convergence then most of the bullet are going to miss the target.

 

That's again your opinion: there are countless reports of US pilots damaging aircraft at 300 yards, whilst the Germans had to get much closer to get an accurate shooting solution. As I said earlier, Ralph Hofer and many others used different convergences for different couple of guns, which gave them a longer convergence area.

The cannons CAN fire at long range... The higher point in the parabolic arc made by a MG 151/20 set with convergence of for firing at 600m was of about 1 meter above the line of sight. Only a 1 Meter. 

 

Those are static measures, you need to put the gunnery in a dogfighting context, where G loads, airspeed and friction all play a part in accuracy: Did you know that the MG151/20 rounds had different muzzle speeds and ballistic performance according to the rounds? Compared to HMGs, it was an imprecise gun.

 

Gyro gunsights are really useful against leveled planes: they are less good for deflection shooting... there it's all instinct (and firing IS mainly instinct). BTW they are useful to HMG as to cannons...

 

No, they were designed to improve deflection shooting. And performed great too. Firing is not about instinct, especially in aerial warfare where all your senses are pushed to the limit, it's about training, training, training. A great deflection shooter was George Buerling, who learned to use his Spitfire guns in an incredible manner, but he did that by constantly training, even when on the ground. 

 

Not quick enough, if they tried to take them down with bombs. How many head on attacks they are going to make in your opinion? 1) it's not a easy tactic (you need to be aligned with the bomber stream). 2) you have few firing seconds. 3) Once you made your attack you have to recatch the stream... while the escort is there for you.

 

I bet that if they used accurate HMGs they would have scored better on first passes, instead they decided to create a wall of explosive rounds, which sometimes worked, sometimes didn't. Why do you think German pilots learned to get so close to their enemy, if, as you say, their guns were ballistically superior? 

As for bomber engagement, they often did a couple of passes and were out of the way. All the air forces that had to face heavy bombers (Italy included) soon learned the lesson that you needed to attack with boom and zoom and aim accurately for the critical points. That's why I think the choice of shooting with heavy guns from a distance, increasing dispersion, wasn't a good idea. 

The development of bigger calibres (Mk103/108) came from the need of being able to hit a target with as less rounds as possible and causing extensive damage. It was a wrong philosophy in my humble opinion, but there you go..

 

Firing everything you had trying to damage the bomber could be the better tactic for average pilots. In that case the more ammo is better; if the guy is a good shot, when few shells of high caliber cannon are enough.

 

You can probably spray a B-17 with 50 MG151/20 and it will still fly. It was about hitting the right spot with a gun accurate enough to let you do it from a distance.

 

If you talk about efficiency surely you know the % of defective shells. Cannons are also more prone to jamming: still the Germans used the mk108. Maybe since it was need one shot to make the difference?

 

The main issue with a jamming gun is that 1) you lose firepower 2) you're at a danger of blowing yourself up 3) you might develop shooting stability problems. The Americans went for redundancy: 2 guns jam? We still have 4.

If a wing MG151/20 would jam, your plane would be rocking around the yaw axis if you fired more

I don't want to enter in this in this discussion: IMO the probability of HE ammo's explosion by API hits was really-really low. IIRC there are not documents about this issue. 

 

it happened, there's guncamera footage that shows it. 

 

Did you speak with every WW2 pilot out there? It's not about what the pilots want: it's about what it's more efficient for the purpose. Quality vs quantity.

 

I didn't, but I talked to a lot of pilots, both veteran and modern. All will tell you "the more ammo, the better!"

 

 

having said this... how do you guys put a break in a long quote to reply?! It's driving me nuts!

[6S.Manu]

having said this... how do you guys put a break in a long quote to reply?! It's driving me nuts!

 

Enter in BBCode (left top corner) and copy/paste the code

ect... 

[Sternjaeger]

Of course!

 

Tony Williams says it on his article (http://www.quarry.nildram.co.uk/CannonMGs.htm)

 

yeah, although defining the M2 a gun "deficient in destructive power" is a bit reductive.. 

 

And don't take all that you see on that page for good, there are several inaccuracies here and there (i.e. the weights and rates of fire of the Berezin and M2 on that specific link).