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Comparing HMG Damage, and issues with .50 cals


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unreasonable
On 5/30/2020 at 4:28 PM, VR-DriftaholiC said:

Found his from another thread. My experience flying online matches this pilots description of the hits damage and amount of time fired. 

 

357-yeager-12oct44.jpg

 

https://combatbox.net/en/sortie/654834/?tour=22

Considering I hit 181 times on 5 targets, 2 burst into flames, one pilot kill and one bailed after leaking everything. I only put a second or less of fire into each target. I don't think there is anything wrong here. Move on.

 

If you put even 50 or more 12.7mm holes into a plane and don't hit a critical system sure they will fly away. Being on the receiving end, I've had a hell of a time staying aloft and definitely couldn't continue the fight. Most of the time end up crashing on the way home or attempting to land. I wouldn't expect six or eight holes to do much.

 

Agree completely.  What I find most interesting about that report is that the writer is sure that two of the 109s bailed out before any of the P-51s had even opened fire!  It could have been a fluke, but more likely it was fairly common that pilots who realized that they were in a hopeless position tactically would bail out even with light or even no damage - just as soldiers usually surrendered in such circumstances.  

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VR-DriftaholiC
6 hours ago, unreasonable said:

 

Agree completely.  What I find most interesting about that report is that the writer is sure that two of the 109s bailed out before any of the P-51s had even opened fire!  It could have been a fluke, but more likely it was fairly common that pilots who realized that they were in a hopeless position tactically would bail out even with light or even no damage - just as soldiers usually surrendered in such circumstances.  

Despite the potentially contradicting video the same pilot wrote the report :P 

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Notice at 3:50 you can see the 'exit wound' from a bullet that has passed through the car. 

My question would be do the calculations of speed loss assume this will happen, or just a small half inch hole for each hit?

I know the DM is an approximation, but that approximation must make some assumptions.

 

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On 5/22/2020 at 9:38 AM, LLv34_Flanker said:

 Mig-15 sure is a different matter, but USAF used API in M3 and those Migs just did not magically turn into torches, even hit tens of times. Russian ace Yevgeny Georgievich Pepelyaev in Korea quoted the .50cals bounced off the skin of Mig. I get the feeling people expect the API be like a SureFlame(tm) device. Expectations vs reality does not meet. And this applies to all guns in game, not only .50cal. I did some testing offline in QMB against Bf109 and Fw190 in a Pony. If I hit at convergence the planes went down with a less than a second burst, usually pilot kill and leaks. Fire was not that regular, but happened. So the guns do work, but needs careful aiming.

 

 

I know I'm incredibly late to the party by internet standards, but jet fuel as it was in use during the Korean War is not at all comparable with high octane avgas with regards to its flammability. Additionally, the speeds at which dogfights happened there were generally much higher, leading to longer flight times of rounds and subsequently much higher energy bleedoff. It's not surprising a lot of those rounds ended up doing negligible damage when they hit.

 

The increase in lethality that came with the M8 API round came from the fact it could get its incendiary component through aircraft skin and into fuel tanks instead of having to rely on an AP projectile to first cause a fuel leak that could then be set alight by a pure incendiary round hitting in the same area.

 

 

 

Anyways, they did a lot of testing on battle damage after the war and shot up several squadrons' worth of planes in the process. Here's the report on it, outlining both testing methodology and findings:

https://apps.dtic.mil/dtic/tr/fulltext/u2/a800394.pdf
 

A word of warning, the server is positively geriatric.

 

Note how pure HE projectiles like German mine rounds were absolute garbage at damaging engines, especially radials, even in their 3 cm versions. However, they were really good at destroying airplane skin.

 

Edited by PainGod85
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On 6/8/2020 at 9:54 AM, PainGod85 said:

 

I know I'm incredibly late to the party by internet standards, but jet fuel as it was in use during the Korean War is not at all comparable with high octane avgas with regards to its flammability. Additionally, the speeds at which dogfights happened there were generally much higher, leading to longer flight times of rounds and subsequently much higher energy bleedoff. It's not surprising a lot of those rounds ended up doing negligible damage when they hit.

 

The increase in lethality that came with the M8 API round came from the fact it could get its incendiary component through aircraft skin and into fuel tanks instead of having to rely on an AP projectile to first cause a fuel leak that could then be set alight by a pure incendiary round hitting in the same area.

 

 

 

Anyways, they did a lot of testing on battle damage after the war and shot up several squadrons' worth of planes in the process. Here's the report on it, outlining both testing methodology and findings:

https://apps.dtic.mil/dtic/tr/fulltext/u2/a800394.pdf
 

A word of warning, the server is positively geriatric.

 

Note how pure HE projectiles like German mine rounds were absolute garbage at damaging engines, especially radials, even in their 3 cm versions. However, they were really good at destroying airplane skin.

 

 

Interesting formula in that. Be forewarned, there's going to be amateur math and I really hope someone can point out some glaring mistakes I made because this seems unbelievable. If my understanding of statistics and interpretation of this text is correct, they have a cumulative distribution function showing the probability of a P-47 suffering a class "A" damage in 'n' hits.

 

Quote

P47formula.JPG.4f87ee8c2daf7fb5113f0ad2186f0f08.JPG

 

Something that sticks out to me in this is that because of the π in the formula, it is capable of producing values greater than 1 and less than 0, both of which are not possible (probabilities can't be negative or greater than 100%). A variant of the same formula with pi appears 1 more time in Table 3, but when calculating B-25 damage probabilities on later pages, they repeatedly leave the pi out.

 

Additionally, and most importantly, if you leave out the π from the P-47 formula and let n = 1, the formula produces the 0.017 value they entered in the referenced "Table 3" (shown below), which represents the overall probability of a single .50 cal hit killing a P-47.

 

Quote

Table3.JPG.94773f8a921cc9807c36b0c9be5da7dc.JPG

 

These two things have me thinking the symbol must be a typo, so I moved forward with that assumption.

 

I plugged in the 0.017 overall number to get a .50 cal cumulative distribution function to work with ( 1 - (1 - 0.017) ^ n ), which looks like the chance of a single success in a binomial distribution, and calculated the mean using n*p and setting it equal to 1. In other words, I calculated the average number of hits a P-47 in this test would theoretically take before suffering damage that would be considered "A" class damage.

 

"A" class damage is defined as damage with the probability that the aircraft will start to fall or go out of control within a period of five minutes from the time it is hit.

 

Quote

ADamage.JPG.115ed0a2b3e033ec2a946befcc98e58e.JPG

 

The mean number of hits for that to occur? 59.

 

If I'm not mistaken, that means, statistically, the 59th hit will down a P-47 from its high six front usually by killing the pilot. With 6 AN/M2 machine guns, that's less than a second of sustained fire. That seems almost too low, especially considering how durable the plane was said to be and the amount of ammo AN/M2 armed US fighters would carry.

 

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9 hours ago, Zirashi said:

 

Interesting formula in that. Be forewarned, there's going to be amateur math and I really hope someone can point out some glaring mistakes I made because this seems unbelievable. If my understanding of statistics and interpretation of this text is correct, they have a cumulative distribution function showing the probability of a P-47 suffering a class "A" damage in 'n' hits.

 

 

Something that sticks out to me in this is that because of the π in the formula, it is capable of producing values greater than 1 and less than 0, both of which are not possible (probabilities can't be negative or greater than 100%). A variant of the same formula with pi appears 1 more time in Table 3, but when calculating B-25 damage probabilities on later pages, they repeatedly leave the pi out.

 

Additionally, and most importantly, if you leave out the π from the P-47 formula and let n = 1, the formula produces the 0.017 value they entered in the referenced "Table 3" (shown below), which represents the overall probability of a single .50 cal hit killing a P-47.

 

 

These two things have me thinking the symbol must be a typo, so I moved forward with that assumption.

 

I plugged in the 0.017 overall number to get a .50 cal cumulative distribution function to work with ( 1 - (1 - 0.017) ^ n ), which looks like the chance of a single success in a binomial distribution, and calculated the mean using n*p and setting it equal to 1. In other words, I calculated the average number of hits a P-47 in this test would theoretically take before suffering damage that would be considered "A" class damage.

 

"A" class damage is defined as damage with the probability that the aircraft will start to fall or go out of control within a period of five minutes from the time it is hit.

 

 

The mean number of hits for that to occur? 59.

 

If I'm not mistaken, that means, statistically, the 59th hit will down a P-47 from its high six, usually by killing the pilot. With 6 AN/M2 machine guns, that's less than a second of sustained fire. That seems almost too low, especially considering how durable the plane was said to be and the amount of ammo AN/M2 armed US fighters would carry.

 

 

59 shots placed arbitrarily on any point in the airframe. This is also stated in the report.

Of course one will eventually find the pilot's brainpan.

 

With an aimed barrage, you usually target a certain section of the plane. IRL, you'd either chew up the cockpit area and turn the pilot into chunky salsa, or stitch a neat band of holes across a wing or the fuselage.

 

The report states how vulnerable certain vital components of the plane are with regards to getting hit by a given type of projectile, and it finds that the pilot is disproportionately vulnerable, even on one of the sturdiest fighters built in WW2 - nothing more, nothing less.

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unreasonable
10 hours ago, Zirashi said:

 

The mean number of hits for that to occur? 59.

 

If I'm not mistaken, that means, statistically, the 59th hit will down a P-47 from its high six, usually by killing the pilot. With 6 AN/M2 machine guns, that's less than a second of sustained fire. That seems almost too low, especially considering how durable the plane was said to be and the amount of ammo AN/M2 armed US fighters would carry.

 

 

The P-47 data is not for shots from six but front below - details are on the table.  

 

 Mean of a binomial is n/p, so ~58.8   I think it is more useful to think in terms of survival.  If you take a large number of P-47s and shoot at them with the 0.017 p of A kill, ignoring B kill effects, you will get A kills on half of them after ~40 hits.    (1- 0.017)^40 = 0.5037   

 

In that report durability is factored in for the pilot kills specifically in terms of how well armoured and shielded by the engine the pilot is from that aspect.  I think in general durability is more useful in the context of structural damage.  

 

Given that the ballistics report that you are quoting is one of the very few statistically rich contemporary documents based on reasonably extensive field tests, it seems unwise to second guess it.

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=1488=PR0T0S

I went to a Air Show back in the mid 2000s and met up with a bunch of the Original IL2ers.

At the show was Bud Anderson Triple Ace who was talking about the effectiveness of the .50 cal.

Answering a question from the audience, he referenced and incident where he strafed an ARMORED locomotive.

 

Think about this. An ARMORED TRAIN ENGINE.

 

He completely obliterated it and there is guncam footage to back it up.

Needless to say I spoke to my buddy at the time CrazyIvan  who was also at that show and rolled my eyes...... whereupon I proceeded to bust his chops. HARD. In good fun of course.

Miss you CrazyIvan and Alex hope you are well.

 

The .50 is no joke.

 

S~!

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2 hours ago, unreasonable said:

 

The P-47 data is not for shots from six but front below - details are on the table.  


High six was in my mind from reading one of the B-25 charts and that was incorrect. I should’ve proofread what I was typing lol.

 

2 hours ago, unreasonable said:

Given that the ballistics report that you are quoting is one of the very few statistically rich contemporary documents based on reasonably extensive field tests, it seems unwise to second guess it.


I wasn’t second guessing the data of the report, I was second guessing my interpretation of it. That’s why I started with “amateur math ahead” and “can someone point out glaring mistakes.” I am not scrutinizing the report to dispute it, I am doing so to learn what I can from it. For example, I still do not understand why theIr P-47 CDF would be formulated in such a way that makes it capable of producing probabilities greater than 1 and less than 0.

 

3 hours ago, PainGod85 said:

 

59 shots placed arbitrarily on any point in the airframe. This is also stated in the report.

Of course one will eventually find the pilot's brainpan.

 

With an aimed barrage, you usually target a certain section of the plane. IRL, you'd either chew up the cockpit area and turn the pilot into chunky salsa, or stitch a neat band of holes across a wing or the fuselage.

 

Excluding the pilot gets me a mean of 142.85, so 143 hits before the next random hit finds something vital in the structure, engine, or fuel tank in a head-on. Assuming 750 rounds per minutes (which is pessimistic for ANM2), that’s sustained hits for 1.9 seconds from 6 guns and 1.43 seconds from 8 guns.
 

As for aimed fire, as can be seen in guncam footage and battle damage pictures of the era, “aimed” when talking about IRL WW2 air gunnery is a bit generous. Especially if we’re talking about a battery of 6-8 rapid firing .50 cal machine guns mounted in the wings of fighters with shotgun pattern convergence, as was done on the P-47, trying to hit an uncooperative target. The pilot could ensure that the shots would be centered over a general area like an entire wing or the center of the fuselage, but the exact components their rounds find, and whether it does lethal damage or not, is effectively up to chance. And to my understanding, that is what that part of the report is testing; what are the chances that single random hit by X round will deal Y damage to Z airplane?


 

 

 

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unreasonable

You right that the report is about the effect of hits - the only place the p of hitting is considered, IIRC, is in the appendices about fighter vs bomber engagement ranges. 

 

"so 143 hits before the next random hit finds something vital" is meaningless.  You must look at the entire distribution. As the report states on page 13 "These probabilities are usually quite small and in general are sufficiently distant from 50% so as to make the underlying binomial distribution an asymmetrical one". (Often very asymmetrical).

 

For instance, suppose you took lots of P-47s in a test to destruction, using any constant probability, what number of hits to down would be the most common?   Answer = 1 hit    The mean number of hits would be observed very infrequently, the mean or more in ~36% of cases for the 0.017 p. 

 

Then there is the additional problem that the more hits are made the less plausible the assumption of independence. Compound and cumulative damage come into play, increasing the p of an A kill for each additional hit, at a very noticeable rate. (We are getting this a lot in FC at the moment where bullets are hitting thin wooden spars....)

 

 

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unreasonable
21 hours ago, Zirashi said:


I wasn’t second guessing the data of the report, I was second guessing my interpretation of it. That’s why I started with “amateur math ahead” and “can someone point out glaring mistakes.” I am not scrutinizing the report to dispute it, I am doing so to learn what I can from it. For example, I still do not understand why theIr P-47 CDF would be formulated in such a way that makes it capable of producing probabilities greater than 1 and less than 0.

 

 

Fair enough - it is a long time since I did formal maths as well, (40+years!) apart from looking at probabilities.  I do not understand the notation of the equation with pi in it very well - I know the intention is to  eliminate the overlaps between categories so as not to double count, but not exactly how. When I do that manually I get very close to their cumulative number but not exactly.  edit - probably just rounding error as they only give 3 decimal places.   Overall p =  1- ((1-pS)*(1-pE)*(1-pP)*(1-pF))    So I am not sure what the pi is doing there either. 

 

 

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E69_geramos109

Rifle calibel is underperforming a lot as well but I will wait to see the entire Dm improvement when they will add fuel, pneumatic systems etc 

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unreasonable
33 minutes ago, E69_geramos109 said:

Rifle calibel is underperforming a lot as well but I will wait to see the entire Dm improvement when they will add fuel, pneumatic systems etc 

 

Evidence?

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Aurora_Stealth
18 hours ago, =1488=PR0T0S said:

I went to a Air Show back in the mid 2000s and met up with a bunch of the Original IL2ers.

At the show was Bud Anderson Triple Ace who was talking about the effectiveness of the .50 cal.

Answering a question from the audience, he referenced and incident where he strafed an ARMORED locomotive.

 

Think about this. An ARMORED TRAIN ENGINE.

 

He completely obliterated it and there is guncam footage to back it up.

Needless to say I spoke to my buddy at the time CrazyIvan  who was also at that show and rolled my eyes...... whereupon I proceeded to bust his chops. HARD. In good fun of course.

Miss you CrazyIvan and Alex hope you are well.

 

The .50 is no joke.

 

S~!

 

I could... believe that, although good ol' Bud does shoot his mouth off sometimes (I know he's still a great pilot) but he also is very aware he's talking to a targeted audience. I'm not that impressed with some of his other claims on 'Dogfight series' which are clearly exaggerated for entertainment value. Again, often for a targeted US audience.

 

For reference, German halftracks were armoured typically only 8 - 10mm thick (sometimes sloped) on the walls. A Panzer IV has 30mm side armour so not as much as you may think. I'd be surprised if the armour on the train engine is more than 15 - 20mm thick as its going to be for protection from rifle type calibers not high penetration weapons coming in at high speed from the air.

 

The speed differential with the train is going to be extremely high, unlike when shooting at an aircraft from behind; where the relative speed difference is going to be way smaller.

 

The .50 calibre has good penetration characteristics which will be enhanced when closing at a very high speed (especially at a side angle).

 

I assume a fair number of bullets reached the train engine and penetration is going to come through eventually somewhere - if the boiler is penetrated then I imagine that would indeed be catastrophic.

 

Its the same story with tank shells, on paper they can't penetrate past their rated numbers, but sometimes they still do due to external, practical factors or just conservative estimates.

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On 5/31/2020 at 3:48 PM, unreasonable said:

 

What I find most interesting about that report is that the writer is sure that two of the 109s bailed out before any of the P-51s had even opened fire!

 

What I find more interesting is that they were claimed as personal kills.  Quite disappointing really.

 

von Tom

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1 hour ago, Aurora_Stealth said:

 

I could... believe that, although good ol' Bud does shoot his mouth off sometimes (I know he's still a great pilot) but he also is very aware he's talking to a targeted audience. I'm not that impressed with some of his other claims on 'Dogfight series' which are clearly exaggerated for entertainment value. Again, often for a targeted US audience.

 

For reference, German halftracks were armoured typically only 8 - 10mm thick (sometimes sloped) on the walls. A Panzer IV has 30mm side armour so not as much as you may think. I'd be surprised if the armour on the train engine is more than 15 - 20mm thick as its going to be for protection from rifle type calibers not high penetration weapons coming in at high speed from the air.

 

The speed differential with the train is going to be extremely high, unlike when shooting at an aircraft from behind; where the relative speed difference is going to be way smaller.

 

The .50 calibre has good penetration characteristics which will be enhanced when closing at a very high speed (especially at a side angle).

 

I assume a fair number of bullets reached the train engine and penetration is going to come through eventually somewhere - if the boiler is penetrated then I imagine that would indeed be catastrophic.

 

Its the same story with tank shells, on paper they can't penetrate past their rated numbers, but sometimes they still do due to external, practical factors or just conservative estimates.

The boiler was my first thought. All you need to do is compromise the boiler enough with your hits to set off a boiler explosion. 

The virtue of the gun configuration on the american fighters would be that they are throwing a large number of AP projectiles in a cloud pattern, resulting in a shotgun-like pattern of hits over a (relatively) wide area. This would increase the likelihood that a projectile would find a weak spot in the armor or a poor-quality weld and damage the boiler, causing a catastrophic explosion. Not unlike a lucky round hitting an ammo box and causing the wing to explode, it's not the destructiveness of the ammo that's important so much as where and what it hits. 
 

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unreasonable
3 hours ago, von_Tom said:

 

What I find more interesting is that they were claimed as personal kills.  Quite disappointing really.

 

von Tom

 

I think most airforces counted manoeuver kills. 

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6 minutes ago, unreasonable said:

 

I think most airforces counted manoeuver kills. 

 

I don't think they did in the RAF.  I think they did in the LW.  I'm not convinced that someone bailing out when they haven't even been fired out merits a "kill".

 

My opinion of course.

 

von Tom

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unreasonable
17 minutes ago, von_Tom said:

 

I don't think they did in the RAF.  I think they did in the LW.  I'm not convinced that someone bailing out when they haven't even been fired out merits a "kill".

 

 

Could be right about the RAF - at least early war. I seem to recall D.Bader complaining that during the BoB enemy aircraft whose pilots bailed under fire out were only counted as a probable! One of things that sticks in the mind because it is so absurd, but I could not tell you where I read that. Maybe "Reach for the Sky", but I no longer have a copy. 

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3 hours ago, von_Tom said:

I don't think they did in the RAF.  I think they did in the LW.  I'm not convinced that someone bailing out when they haven't even been fired out merits a "kill".

You needed to fire at least one (1) bullet in that fight in order to be eligible for a kill.

 

Charles Lamb found that out the hard way when he made a Fiat biplane impact the water while engaging his Swordfish. He flew home happy, thinking he just had scored a kill. Yet back home, they told him without him firing even once, he wouldn't  be eligible for a kill. He certainly would not forget that fight. Before the Fiat smashed into the water, the Fiat shot at the Swordfish and back home Lamb found a bullet stuck in his chute pack a fraction of an inch below his private parts.

Edited by ZachariasX
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Why is nobody posting guncam clips in those threads?

So much real video evidence of the .50 turning Jerry and Hiro boys into burnt ends.

 

 

 

 

 

 

Edited by ACG_Onebad
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unreasonable
11 minutes ago, ACG_Onebad said:

Why is nobody posting guncam clips in those threads?

So much real video evidence of the .50 turning Jerry and Hiro boys into burnt ends.

 

 

We have seen them all before. Why do you think people show these clips?   What do you think they show? 

 

We do not have guncam clips of them not turning Jerry into burnt ends, although we know that must have happened too.  It is like taking the few good moments from Ricky Gervais' TV shows and claiming these prove he is a great comic.

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4 minutes ago, unreasonable said:

 

 It is like taking the few good moments from Ricky Gervais' TV shows and claiming these prove he is a great comic.

That would be a pretty far-fetched claim even for a flight sim forum!

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E69_geramos109
7 hours ago, unreasonable said:

 

Evidence?

just some test ofline stuka using the pods vs planes. they seem to eat cracy amount of ammo. But I will not make proper test till the Dm will be finished.

Edited by E69_geramos109
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=1488=PR0T0S

One only needs to do a quick search of youtube to see what the penetrative power of just one .50 cal round can do at 2000 meters.

Never mind the much shorter distances generally involved in air combat.

 

500-800 rpm per gun

6 guns on a mustang

 

6 guns firing @ approximately 10 rounds per sec

In a more or less conical pattern.

 

Its been 20 years and still the same idiotic arguments about hitting power of .50 vs 20.

I believe someone else correlated the 'weight' of fire in this thread as 1.6x  ??? of 20mm = EXACTLY

 

NO ONE who has fired even a single .50 machinegun in real life is going to question its effectiveness - certainly not against soft targets like aircraft.

Sad to see this raging so long ...... but we can have rocketship K4s, Doras and 262s.

 

Oh well .... I will let the younger whippersnappers duke it out. As someone mentioned about guncam .... you could post a 1000 videos and it won''t mean a thing.

Perhaps you should recalibrate your monitor ahahahaha.

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I might as well throw this in here since people are discussing the 50s.

 

 

In 4.006 I did a series of similar shoots against P-38, B-25 and Me262 fuel tanks, as well against Me262 engines to compare with the testing in the airplane vulnerability study mentioned above.  On average it took about 32 rounds to light a P-38 fuel tank on fire and 39 rounds against a B-25, using the single AN/M2 in the A20 (fired in short bursts).  This compares pretty poorly to the 68% chance of a fire they reported when attacking damaged fuel tanks (damaged in the test meant that the tank had been shot at least once with .50cal already).  Against the Me262  it was again around 39 rounds on average, vs a 71% chance of fire recorded in the real life test.  Obviously we're using AP, rather then the API-T in the real world test, but that just goes to show what an enormous difference API should make - the second burst (if not the later rounds of the first burst) fired should theoretically ignite the tank in most cases.

 

Against the Me262 engines it took an average of 6 rounds from the rear and 9.7 from the front to knock out the engine.  In the test above, early jet engines (from a P-59) had a 50-60% chance of being knocked out from a single hit of .50 API-T. 

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I have been flying tons of missions against Stukas (before I realized they were killing my sim with crashes and blurries) and Ju-88s, with .50 cal planes, and most kills occur when I finally murder the pilot directly. Fires are rare and even rarer still is an airplane that cannot stay in the air due to engine or controls damage.

 

Seems not quite right to me.

 

Update:

 

Did a mission, P-40E vs. JU-88. Took extra ammunition option. Set to "invulnerable" so that I would not have to worry about the enemy gunners.

 

Parked behind the JU-88 and pretty quickly killed everyone besides the pilot, so I deliberately shifted my fire to the wings and engines. Emptied the entire magazines and then another 300 rounds or so on the second load before the JU finally could not stay in the air any longer. Just went back and forth hosing down the target, really kind of remarkable that it just kept tanking the shots and flying on. It was streaming so much fuel I can't see how it would not have at least caught fire (never mind the engines stopping).

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On 6/15/2020 at 9:04 PM, unreasonable said:

 

We have seen them all before. Why do you think people show these clips?   What do you think they show? 

 

We do not have guncam clips of them not turning Jerry into burnt ends, although we know that must have happened too.  It is like taking the few good moments from Ricky Gervais' TV shows and claiming these prove he is a great comic.

 

I get your point - guncam clips only (or at least mostly) show the successful victories. Even then, they're a good source of first hand footage of what a row of .50 cal does to an aircraft. Fires are common in those, as is a significant amount of debris. In the more high res ones, you can easily see parts of the skin missing which would be enough to cause significant instabilities on their own even without fires or systems damage. But to say we don't have guncam clips of German aircraft burning under .50 cal fire is plain wrong. Even the most common ones available on YT have plenty of those.

 

Also a guy with 1488 in his name liked my previous post and ugh, I'd like to say that I have nothing to do with the ideology those numbers represent.

Edited by ACG_Onebad
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unreasonable

The whole question of fires is a fair one IMHO because to date the game does not yet explicitly model an incendiary round for the 50 cal, (or an incendiary/explosive bullet for 303s and similar for that matter). Then the addition of a more detailed fuel system to the is also in the pipeline, so that might have effects too.   

 

Of course incendiaries would make fires more common in the real world - but they are not some kind of instant flame thrower. As 50 cal API round would very rarely, according to the ballistics study discussed above, down a plane due a fuel tank on fire with one hit in a real moving plane.  Almost all fires come when you breech a tank, in a certain range of conditions, then ignite the fuel flow with a later hit.    "The cal .50 ammunition [API-T M20] caused no single-shot fires which had any chance of causing the plane to crash within five minutes".  

 

It is possible that the current BoX "ball round" is actually causing fires at the rate the US researchers estimated for API - it is possible for us to test in the game, by recreating something like the US test conditions, but extremely time consuming. I will not be doing it: it was hard enough doing this for 20mm HE.  

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On 6/16/2020 at 12:58 AM, MattS said:

Emptied the entire magazines and then another 300 rounds or so on the second load before the JU finally could not stay in the air any longer.

The difference between stronk Junkers and flimsy Sopwith. Ball rounds only hurt the weak.

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69th_Mobile_BBQ

 When I can give a 109 a 1/2 second of machine gun (and maybe 1 20mm round) across the nose and set his engine on fire in a Yak-1.69 but, rarely close to doing the same in a P-51..... 

When I can break wingtips off in a Yak-1.69 with a 1/2 second burst of mg and a 20mm round but, need to hit the same area 4 or 5 times with .50's at near-perfect convergence....  

When I can plow the side panel of and enemy's cockpit with (say it with me) a half second burst of mg and a cannon shell and cause enough injury for a quick bleed-out but, do jack sh+t with .50s.....  

When no matter what I hit with causes not even the shudder from a wing hit on the AI that's stuck in the "stupid loop" circle routine.....  

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Aurora_Stealth
2 hours ago, 69th_Mobile_BBQ said:

 When I can give a 109 a 1/2 second of machine gun (and maybe 1 20mm round) across the nose and set his engine on fire in a Yak-1.69 but, rarely close to doing the same in a P-51..... 

When I can break wingtips off in a Yak-1.69 with a 1/2 second burst of mg and a 20mm round but, need to hit the same area 4 or 5 times with .50's at near-perfect convergence....  

When I can plow the side panel of and enemy's cockpit with (say it with me) a half second burst of mg and a cannon shell and cause enough injury for a quick bleed-out but, do jack sh+t with .50s.....  

When no matter what I hit with causes not even the shudder from a wing hit on the AI that's stuck in the "stupid loop" circle routine.....  

 

@69th_Mobile_BBQ

 

Appreciate your frustration, but the following applies here:

 

The Yak-1 has a centralised armament (mounted on the nose, i.e. close to the centre-line of aircraft), so you can be more precise with gunnery and be more efficient with hits on target in that aircraft. It's the configuration of the guns which makes the difference here. Centralised armament is a technical advantage, it is a major factor in hit accuracy and concentration. You won't consistently replicate this with wing-mounted weapons. Period.

 

Unfortunately, you can't directly equate a .50 calibre round to a 20mm shell no matter which way you put it.. even statistically. Saying three or four bullets of .50 calibre compare directly to one 20mm is too simplistic and misses the fact the latter is a different type of shell - a cannon shell explodes and therefore can cause a shudder effect. The .50 calibre rounds do not explode and so do not cause a shock-wave and so the aircraft they hit don't tend to shudder. There are exceptions, e.g. a lucky hit on a Fw190's wing mounted 20mm shell containers.. but they tend to be infrequent and not caused by the .50 calibre bullet alone.

 

One 20mm round is one 20mm round - its just a different kind of weapon. The explosive effect of the 20mm does area damage with single hits, the .50 calibre does not. A heavy burst of .50 calibre will disturb the aircraft aerodynamically in other ways with a spread / shotgun effect.

 

As another note, once the fuel system is fully modelled, AP-I rounds can then be included, but they will not be silver bullets.. so please don't mislead yourselves into this.. they will just enhance the probability of lighting and burning out fuel tanks. They will also not cause an explosion unless they hit something explosive (i.e. bullets/shells contained in the wings or something extremely volatile). Unlike in the movies, fuel tanks tend to burn not explode. How strongly they burn will depend on the fuel as well, i.e. 150 octane will burn far easier than 100 octane... MW50 will also probably burn like hell. The AP-I rounds may also have less penetrative power due to their construction (i.e. its not a ball round as it has the hollow section inside for the incendiary filler) ... a mixed load-out could help though.

Edited by Aurora_Stealth
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4 hours ago, ZachariasX said:

The difference between stronk Junkers and flimsy Sopwith. Ball rounds only hurt the weak.

 

Haha no doubt.

 

I get that expecting an insta-kill for any careless shot is unreasonable, but in this case I really was just HOSING that Ju-88 down. Fortunately I captured some video if needed.

 

Ironically I did a QMB mission last night where I managed to shoot down THREE Pe-2s without a single scratch on my P-40 (two engine fires and a pilot kill). I think we're at a place where the Ju-88 is actually harder to kill now.

Edited by MattS
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69th_Mobile_BBQ
6 hours ago, Aurora_Stealth said:

 

@69th_Mobile_BBQ

 

Appreciate your frustration, but the following applies here:

 

The Yak-1 has a centralised armament (mounted on the nose, i.e. close to the centre-line of aircraft), so you can be more precise with gunnery and be more efficient with hits on target in that aircraft. It's the configuration of the guns which makes the difference here. Centralised armament is a technical advantage, it is a major factor in hit accuracy and concentration. You won't consistently replicate this with wing-mounted weapons. Period.

 

Unfortunately, you can't directly equate a .50 calibre round to a 20mm shell no matter which way you put it.. even statistically. Saying three or four bullets of .50 calibre compare directly to one 20mm is too simplistic and misses the fact the latter is a different type of shell - a cannon shell explodes and therefore can cause a shudder effect. The .50 calibre rounds do not explode and so do not cause a shock-wave and so the aircraft they hit don't tend to shudder. There are exceptions, e.g. a lucky hit on a Fw190's wing mounted 20mm shell containers.. but they tend to be infrequent and not caused by the .50 calibre bullet alone.

 

One 20mm round is one 20mm round - its just a different kind of weapon. The explosive effect of the 20mm does area damage with single hits, the .50 calibre does not. A heavy burst of .50 calibre will disturb the aircraft aerodynamically in other ways with a spread / shotgun effect.

 

As another note, once the fuel system is fully modelled, AP-I rounds can then be included, but they will not be silver bullets.. so please don't mislead yourselves into this.. they will just enhance the probability of lighting and burning out fuel tanks. They will also not cause an explosion unless they hit something explosive (i.e. bullets/shells contained in the wings or something extremely volatile). Unlike in the movies, fuel tanks tend to burn not explode. How strongly they burn will depend on the fuel as well, i.e. 150 octane will burn far easier than 100 octane... MW50 will also probably burn like hell. The AP-I rounds may also have less penetrative power due to their construction (i.e. its not a ball round as it has the hollow section inside for the incendiary filler) ... a mixed load-out could help though.

 

I'd probably agree but, it's the LMG on the Yak-1.69 that's the fire starter, not the cannon shell.  Test it in QMB if you don't believe me.  

I'd also say that 1, 20mm shell is obviously not comparable to a .50 round, but 20 - 30, .50 rounds all hitting in the same area, all with converged trajectories, all carving their own paths that intersect with the path(s) of other .50 rounds from the same burst, should be a hell of a lot more destructive than 1 or 2 cannon shells. 

 

Centralized armament is good for shots where the target provides a good profile.  When you're on the dead six of a plane with a skilled pilot, they can literally "do a barrel roll" to keep off of the same plane as the centerline axis of the attacker's gun until their ammo runs dry. Oddly enough a well-skilled pilot can make you waste more ammo the closer you are.  In that case, I'd take wing mounted convergence any day.  The idea is that the bullets fill a much larger cubic space vs. centerline.  Both have their advantages and disadvantages of course, but the requirements for successful gunnery against an enemy target at medium to close range goes to the wing mounted configuration.

That, and the USAAF would have NEVER chosen the .50 if it was only just-as (or less) effective than a ShKas. 

 

I'll see if I can dig it up, but I have seen P-51 pilot interviews where it was stated that they were so close to the enemy that they had to either skew the gunsight left or right to hit them with only 1 wing's worth of guns (3).  They still shredded them and got the kill with half the fire power of the plane available.  

 

Also, it doesn't matter what the plane is hit with, if there's enough of it hitting, especially on the left wing of a plane that's in a hard-right bank (as they tend to do when they go into the AI loop), it should cause a visible disruption.  I wasn't specifying only the .50's there either.  Heavy shells don't seem to have any effect either from what I've observed.

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-SF-Disarray

I've recently been running some tests on various guns, trying to figure out what is going on. The results I've found are a little odd. The test runs as follows: Pick a target plane and establish baseline maneuverability and sustained speed. This is the standard that will be measured against. In my first test a P-40 was used as a target plane and I made a short burst from a P-51's 6 guns configuration at convergence into the midsection of the right wing; all shots were taken from the 6 o'clock position. After this hit there was no observed change in either speed or maneuverability. For the second test we kept the target the same but switched to a 109 G14 for a shooter. I shot the P-40 in the midsection of the right wing with a short burst of just the 131's, observing 1-2 HE hits. The P-40 slowed down by about 25 MPH and was markedly less maneuverable, to the point of being combat ineffective. After a reset a third test was conducted with the G14's 20 mm cannon. The shot was to the midsection of the right wing. One HE hit was observed and it is possible that an AP round hit as well. The effect on the P-40 was roughly the same as with the 131 hits, a decrease in speed of 25 MPH and a marked decrease in maneuverability. At no point, in any test, was damage to control systems reported. This test was done in MP on the CombatBox training server with few other people in it. I was the shooter in all three tests and the target plane was flown by the same person in all tests. The ping to the server was roughly the same for both of us, we live some 50 miles apart.

 

I have run similar tests using other planes, both Allied and Axis, as a target and the results are roughly the same, M2's have almost no effect on the target plane and the 131's hit like trucks. I cannot account for this difference based on the projectiles. The 131 round packs an HE charge, sure, but it is only .9 grams of PETIN and I can't imagine that 2 guns firing such rounds half the time could account for more effective damage than 6 guns firing heavier rounds at a higher velocity. That the effects of the 131's in a short burst is doing damage equivalent to 1 or 2 rounds from a 20 mm cannon is bazaar. The major stand out results from this test are the effectiveness of the 131's and seemingly total lack of effect from the M2's where hits to the wings are made. This holds true outside of ideal conditions as well. I have often hit planes with many .50 rounds from a Mustang and seen little effect in maneuverability or speed and have been on the receiving end of such hits and observed little effect in my plane. Likewise I have hit planes with a few MG hits from 131's and observed a marked decrease in the combat effectiveness of the other plane, and been hit by 131's and lost all ability to carry on fighting more times than I care to count.

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Aurora_Stealth
5 hours ago, 69th_Mobile_BBQ said:

 

I'd probably agree but, it's the LMG on the Yak-1.69 that's the fire starter, not the cannon shell.  Test it in QMB if you don't believe me.  

I'd also say that 1, 20mm shell is obviously not comparable to a .50 round, but 20 - 30, .50 rounds all hitting in the same area, all with converged trajectories, all carving their own paths that intersect with the path(s) of other .50 rounds from the same burst, should be a hell of a lot more destructive than 1 or 2 cannon shells. 

 

Centralized armament is good for shots where the target provides a good profile.  When you're on the dead six of a plane with a skilled pilot, they can literally "do a barrel roll" to keep off of the same plane as the centerline axis of the attacker's gun until their ammo runs dry. Oddly enough a well-skilled pilot can make you waste more ammo the closer you are.  In that case, I'd take wing mounted convergence any day.  The idea is that the bullets fill a much larger cubic space vs. centerline.  Both have their advantages and disadvantages of course, but the requirements for successful gunnery against an enemy target at medium to close range goes to the wing mounted configuration.

That, and the USAAF would have NEVER chosen the .50 if it was only just-as (or less) effective than a ShKas. 

 

I'll see if I can dig it up, but I have seen P-51 pilot interviews where it was stated that they were so close to the enemy that they had to either skew the gunsight left or right to hit them with only 1 wing's worth of guns (3).  They still shredded them and got the kill with half the fire power of the plane available.  

 

Also, it doesn't matter what the plane is hit with, if there's enough of it hitting, especially on the left wing of a plane that's in a hard-right bank (as they tend to do when they go into the AI loop), it should cause a visible disruption.  I wasn't specifying only the .50's there either.  Heavy shells don't seem to have any effect either from what I've observed.

 

I couldn't comment about the ShVak machine gun causing fires as I'm not really familiar with it.. but, definitely nothing wrong in collecting more info for comparison.

 

I'm pretty sure if you are hitting the target with 40 - 50 bullets or so in a concentrated area you are going to cause some decent damage to a fighter, the question is - are you are in fact hitting the target that much and to what concentration.. or is it just an estimation of bullets sent across in that firing time. If you can get three guns from one wing on target great - but its often a matter of a split second in these situations and that might not be decisive.

 

The choices of gun were (especially with the US getting across the world) often down to logistics, and what was available - .303 calibre was used on RAF fighters in 1940 because there was lots of stock and ammo. Similar story for USAAF for .50 calibre. The RAF quickly changed to 20mm, but used.50 calibre on later aircraft as well as this was supported by the US supply chain. I think there was actually some desire for it in USAAF service but this never came to fruition, especially as Hispano who produced the cannons for the RAF was a european company and little development and testing was originally made in the US (as far as I know). By comparison the Germans spent unbelievable amounts of time and money for armament production in specialist facilities including specifically for PETN production. 'Abandoned engineering' series is very good on this - the efforts they went to, to ensure their ammunition was of the highest grade is absolutely ridiculous really - no joke.

 

Agreed, there are advantages and disadvantages of both.

 

4 hours ago, -SF-Disarray said:

I've recently been running some tests on various guns, trying to figure out what is going on. The results I've found are a little odd. The test runs as follows: Pick a target plane and establish baseline maneuverability and sustained speed. This is the standard that will be measured against. In my first test a P-40 was used as a target plane and I made a short burst from a P-51's 6 guns configuration at convergence into the midsection of the right wing; all shots were taken from the 6 o'clock position. After this hit there was no observed change in either speed or maneuverability. For the second test we kept the target the same but switched to a 109 G14 for a shooter. I shot the P-40 in the midsection of the right wing with a short burst of just the 131's, observing 1-2 HE hits. The P-40 slowed down by about 25 MPH and was markedly less maneuverable, to the point of being combat ineffective. After a reset a third test was conducted with the G14's 20 mm cannon. The shot was to the midsection of the right wing. One HE hit was observed and it is possible that an AP round hit as well. The effect on the P-40 was roughly the same as with the 131 hits, a decrease in speed of 25 MPH and a marked decrease in maneuverability. At no point, in any test, was damage to control systems reported. This test was done in MP on the CombatBox training server with few other people in it. I was the shooter in all three tests and the target plane was flown by the same person in all tests. The ping to the server was roughly the same for both of us, we live some 50 miles apart.

 

I have run similar tests using other planes, both Allied and Axis, as a target and the results are roughly the same, M2's have almost no effect on the target plane and the 131's hit like trucks. I cannot account for this difference based on the projectiles. The 131 round packs an HE charge, sure, but it is only .9 grams of PETIN and I can't imagine that 2 guns firing such rounds half the time could account for more effective damage than 6 guns firing heavier rounds at a higher velocity. That the effects of the 131's in a short burst is doing damage equivalent to 1 or 2 rounds from a 20 mm cannon is bazaar. The major stand out results from this test are the effectiveness of the 131's and seemingly total lack of effect from the M2's where hits to the wings are made. This holds true outside of ideal conditions as well. I have often hit planes with many .50 rounds from a Mustang and seen little effect in maneuverability or speed and have been on the receiving end of such hits and observed little effect in my plane. Likewise I have hit planes with a few MG hits from 131's and observed a marked decrease in the combat effectiveness of the other plane, and been hit by 131's and lost all ability to carry on fighting more times than I care to count.

 

I'd strongly recommend doing all tests offline, as we have debated the packet loss and netcode issues many times already - better to keep things clean without adding in server related / ping related variation. I know that's not very confidence building, but for testing purposes it eliminates any possibility of smaller effects and details not being correctly sent by data stream. Also FYI, (I'm sure you have already) but if you haven't - definitely do the Combat Box MTU packet loss check on the website.

 

Well you said it yourself - the MG131 despite its similar size calibre to the .50 calibre uses PETN, HE and incendiary filler in its shells - you don't need very much PETN to cause an extremely shocking amount of damage that even TNT cannot closely replicate - look on youtube. A burst of these rounds over an area at a high rate of fire is absolutely going to create skin damage across a broad area. And those were only the hits you saw, what about the ones that were absorbed in the structure? furthermore the dev's have said that the visual damage shown often does not show the full extent or depth of damage actually done with the calculations so its very difficult to actually say accurately how many hits were absorbed into the aircraft overall.

 

From what you said, I absolutely agree two rounds of 13mm isn't likely to do all that - but I also suspect many more actually did hit target. If you only hit with one wing's gun (three .50 cals) versus two MG131's in the nose, I'm willing to bet the probability of doing broad skin/aerodynamic damage is actually going to be higher in the latter because the damage is much higher per hit but has a similar rate of fire while being concentrated around that centreline.

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-SF-Disarray

It is not possible that I only hit with one wing's guns in these test with the P-51. They were conducted in controlled, ideal, conditions. For clarity, I fired the rounds from 250 m in all cases for the tests. The labels with the distance to target are activated on that server and it was part of the reason I chose that server for these tests. My gun convergence is set to exactly 250 m. All six guns hit the target, minus any rounds that would have missed by natural inaccuracies from the guns themselves. I did not aim at the center of the target, I aimed for exactly where I hit. The bursts that I fired were of such a short length there is little chance that significantly more rounds hit the target than I observed hitting the target; this was the case for all the shots taken. I am well aware that the visual and physical damage models do not track well. It is for this reason that I discounted all visual data as it pertains to the damage done to the target aircraft. I only gathered data that pertained to the physics at play in the aerodynamic model, specifically speed before and after and flight handling before and after being hit. I did note that I observed the rounds hitting but if you are going to argue that the visuals in the game are so inconsistent with the sim that I can't visually confirm hitting the plane then there are significantly larger problems at play here.

 

Yes, the 131 rounds contain a small, very small, explosive charge. The 20 mm rounds have a significantly larger charge in them. Why is it that, at most, 1 HE and 1 AP round impacting a plane behaving in a similar way to how, being very generous here, 4 or 5 HE rounds from a 131 HMG?  For further clarity the 131 HE round packs .9 g of PETN into it. The 20 mm HE Minengeschoss rounds pack between 18.6 and 25 g depending on the exact model. So given the most charitable estimation of the rounds I hit with and the most favorable HE load for the 20 mm round i hit with, that accounts for 4.5 g of PETN applied to target vs 18.6, or just a little less than 25% the explosive mass but a similar effect on the target. The numbers don't add up. I'd have to have hit with 16 to 20 rounds for this to make sense and I'm confident I didn't even fire that many.

 

As for server load, network latency and packet loss. Well there is nothing I can do about that. I can comment that, as I noted before, the server where these tests were conducted was at a very low population at the time of the tests. There was, to my knowledge one other person on that server at the time of the tests who was not involved in the actual testing itself. My ping to the server is typically under 100 ms and very often below 80 ms. The person I was conducting the test with would be very likely to have similar pings given our relatively close physical proximity. And, again, we have bigger issues at play here if a server can't keep up with 2 or 3 planes at the same time. As for conducting the tests off line this provides significant difficulties because you can't collect accurate data from a plane you are not in. Maybe you can tell how well a plane can maneuver when you aren't at the controls, but I can't. At any rate I don't think any error that may have been injected into the tests by being conducted online could account for the disparity that was observed.

 

I don't expect you to just take me at my word. Go and do the same tests I did for yourself and see the results for yourself. I'm planning on further testing, to include Soviet guns into the mix mostly, and if you really want I'll film the tests

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unreasonable
4 hours ago, -SF-Disarray said:

 

 

I don't expect you to just take me at my word. Go and do the same tests I did for yourself and see the results for yourself. I'm planning on further testing, to include Soviet guns into the mix mostly, and if you really want I'll film the tests

 

 

Convincing us that there is a mistake in the system is not going to help - you have to convince the developers. They have repeatedly said that tests from online are not considered.

 

Additionally, you have to show a particular result enough times.   Damage depends on the characteristics of the round, range etc but also on an RNG.  The outcomes of a single test, or a small number of tests, may not reflect the true distribution of outcomes.  This is why the all the videos of single incidents people post can only ever show what can happen, not what usually does happen.

 

"As for conducting the tests off line this provides significant difficulties because you can't collect accurate data from a plane you are not in."

 

True, but the developers can.   @AnPetrovich   has a robot that can fire set numbers of shots at specific hit boxes under defined conditions. (He described it in a similar discussion in the FC forum).  They know that we cannot test to the same level of accuracy, but we have to do enough to make a good case, in terms defined by them.    

 

 

 

 

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Rattlesnake

Thanks OP, seeing a new release come up gave me hope, you saved me some testing time.

Oh well, life has certain compensations if you keep and open mind and are willing to look for them.

P-47M Gunnery

 

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