Thoughts on the aerodynamic penalty for .50" cal hits.

[Bremspropeller]

19 minutes ago, [TLC]MasterPooner said:

Your redraw hardly changes the result. It still shows rather large exits far more often than not. And most of that missing paint is not from the fire, that is from the paint coming off from the exits and entrance points. This happens all the time with bullet impacts and is not a novel phenomenon. Some of the discoloration was from the fire but the holes and the missing paint is not.

 

There is no evidence the exit-hole sizes are caused by the projectile - actually the only evidence in place is that there was substantial fire-damage. Both by form and surrounding secondary damage caused by heat. Two out of five exits show a rather underwhelming hole-size and are closer to what one could expect even in conjunction with ripping effects.

The larger one of those two small holes shows fire-damage.

 

You can believe whatever you want - it's not neccessarily true, though.

 

All those holes in the car are sized between the two small exit-holes and the top (read: most outboard) exit hole.

Taking the fuel-cap in relation to the car-mirror.

Edited July 6, 2020 by Bremspropeller

[LColony_Kong]

4 minutes ago, Bremspropeller said:

 

There is no evidence the exit-hole sizes are caused by the projectile - actually the only evidence in place is that there was substantial fire-damage. Both by form and surrounding secondary damage caused by heat. Two out of five exits show a rather underwhelming hole-size and are closer to what one could expect even in conjunction with ripping effects.

The larger one of those two small holes shows fire-damage.

 

You can believe whatever you want - it's not neccessarily true, though.

 

All those holes in the car are sized between the two small exit-holes and the top exit hole.

Taking the fuel-cap in relation to the car-mirror.

That is patently absurd. 3 out of the Five show huge exit holes, and the 4th is still larger than the exit. And the point of the car images and other images is not that every single impact is massively larger, but most are, and all are larger than the entrance. Damage like you see in that image would also have not been caused by a fire. Fires do not do that to metal like seen in this image. The jagged irregular exits are caused by physical trauma. If the fire was hot enough it might melt some of the metal but it would not cause the sort of irregular damage you see in the images. The fact that bullet exits are significantly larger in general than the entrance is not a controversial point of fact.

23 minutes ago, Aurora_Stealth said:

@[TLC]MasterPooner

 

FYI

 

 

 

 

  the photo shows damage from an APEI shell i.e. using a form of high explosive not invented for the M2 until after the war hence the holes being much much larger than any entrance or exit holes that just the bullet typically produce on its own as ball / AP.

 

 

Where is the source that APEI was the round being used, or even used in the ammunition belt.

[Bremspropeller]

33 minutes ago, [TLC]MasterPooner said:

Damage like you see in that image would also have not been caused by a fire. Fires do not do that to metal like seen in this image.

 

Yeah, right...

 

 

[sevenless]

On 6/23/2020 at 1:32 AM, alpino said:

also interesting to see the kill here between 3:42 and 3:49, you can see some nasty damage to the left wing followed by loss of control 

 

Thanks for that. Very interesting Fw190 sequence here. Either explosion of the ammo box or fuel tank. My guess would be it is the ammo box.

 

 

 

Edit: Found it. Yep seems like the ammo box or the 2 compressed air bottles for the Mk108. Still think it is the ammo box going boom here.

 

 

Edited July 6, 2020 by sevenless

[Reggie_Mental]

On 5/15/2020 at 9:25 PM, zdog0331 said:

Its though to say.  Its a decent test @71st_AH_Barnacles however what i think is missing is looking at a model standpoint and figure out how much surface area was cleared up by the various modifications that was done to the p-39. (For the weight you can compare the numbers ingame to that much weight difference by using a different fuel load to calculate that) You can then use those numbers to get a rough estimate for how much surface area those 50 cal holes represent and compare that to how large the holes for a 50 cal bullet should be which does have a lot of data from various sources.

 

There are also a lot of other aspects that effect this, for example wing design.  Literally hitting bugs in the p-51d can cause problems.  A single fly can decrease the effective surface area by 1 square inch and getting a bunch of bug hits on the wings can actually cause the plane to fly very poorly due to how perfect the wing design is.  And things like bullet hits were very problematic if they compromised the leading edge of the wing.  Where other planes this isn't an issue.  Literally you cannot fly a P-51 if there is a large amount of bugs out like you will see from time to time the american Midwest due to this issue.  So technically 1 burst of .50 cals to the leading edge of that plane would cause it to be horribly difficult to control and loose a significant amount of speed and even more lift.

I would have thought bugs clogging up the radiators would have been a greater danger to the aircraft performance.

[gimpy117]

but we haven't gotten down to the point of: why does it seem that 1 MGFF mine shell can do something that 60 .50 cals are can't even do? that does not seem right at all. you mean to tell me 60 half inch sized entry and 60 exit can't even slow down a plane like one mine shell? 

 

I don't buy it 

Edited July 11, 2020 by gimpy117

[-SF-Disarray]

To add a twist to that question, why can 3-5 MG131 rounds do the same kind of damage the 1 MGFF mineshell can do?

[alpino]

lol

[EwokSithLord]

I used some mission-builder missions to test the effect of .50 AP on the FM by shooting at the right wing of a 190D and Bf109G14 with the P38J

 

 

US .50 AP has no effect at all on the flight model. After around 40 hits to the right wing, the wing breaks off. The plane does not require any control surface deflection to maintain straight flight. .50s don't alter the flight path at all until the wing is broken. Tested on right wing of Fw190D9 and Bf109G14

 

Tested same scenario with 20mm on P38 to ensure the AI wasn't on rails and that the recording wasn't bugged. With 1 20mm hit, the flight path is altered and the AI uses ailerons to maintain straight flight. See 2:00 mark

 

.50s CAN kill pilots and damage critical systems, but have no actual effect on the FM unless they break off an entire wing, flap, control surface, or landing gear door. Holes in the wings have no effect

 

 

 

Edited July 22, 2020 by EwokSithLord
Add timestamp for 20mm hits

[EwokSithLord]

Pretty sure the 50s have very very very little or no effect at all on DM

Did some tests here, 30-40 hits have no noticeable effect on an AI trying to maintain level flight in formation until the wing falls off. The AI doesn't use any control surface deflection at all as it isn't suffering from any drag or loss of lift in the damaged wing.

 

Later in the video I shoot a plane in the wing with a 20mm, and you can see the plane wobble and use control surfaces to maintain course.

 

[BCI-Nazgul]

1 hour ago, EwokSithLord said:

Pretty sure the 50s have very very very little or no effect at all on DM

Did some tests here, 30-40 hits have no noticeable effect on an AI trying to maintain level flight in formation until the wing falls off. The AI doesn't use any control surface deflection at all as it isn't suffering from any drag or loss of lift in the damaged wing.

 

Later in the video I shoot a plane in the wing with a 20mm, and you can see the plane wobble and use control surfaces to maintain course.

 

Exactly what we've been saying all along.   Today, 3 sorties, 23 hits, 99 hits, 16 hits (if you believe the Combat Box stats) with M2 .50s, NOT ONE SINGLE winning engagement.  The historical average number of US .50 hits to down an enemy was between 14 and 20.   But, in game, even 99 hits is not enough.  I read a comment the other day that a guy had 200+ hits and it didn't take down the target!  I've read many theories about why this is happening:  DM not complicated enough, network/netcode issues, no API, M2 pilots can't aim, etc... but the fact remains that M2 armed planes are flying have been flying around with one-hand tied behind their back (online at least) for months.  I'd happily trade 6 - 8 M2's in for a couple 131's or 12.7 mm's right now.

Edited July 22, 2020 by BCI-Nazgul

[-SF-Disarray]

This tends to put to rest the argument that it is net code related. It also raises some questions about the 'second level of visual damage' theory. In the first 190 clip a large hole opens up on the wingtip at about the one minute mark. This is part of that second level of damage isn't it? That should have required the plane to do something to maintain course if the aerodynamic damages are tied to this second level of damage. Further, it tends to argue against the issue being convergence related as many have commented as the guns in the 38 are so close as to make it largely irrelevant.

[Bremspropeller]

4 hours ago, EwokSithLord said:

US .50 AP has no effect at all on the flight model.

 

Ever been hit in the wings by a few rounds of fifty?

[41Sqn_Skipper]

1 hour ago, Bremspropeller said:

 

Ever been hit in the wings by a few rounds of fifty?

 

Only by friendly fire, had to RTB as flying straight and level was difficult afterwards. 

[Bremspropeller]

1 minute ago, 41Sqn_Skipper said:

Only by friendly fire, had to RTB as flying straight and level was difficult afterwards. 

 

That's about on par with my experience. A couple of hits into the wing and you're pretty much out of the fight.

[Aurora_Stealth]

6 hours ago, EwokSithLord said:

I used some mission-builder missions to test the effect of .50 AP on the FM by shooting at the right wing of a 190D and Bf109G14 with the P38J

 

 

US .50 AP has no effect at all on the flight model. After around 40 hits to the right wing, the wing breaks off. The plane does not require any control surface deflection to maintain straight flight. .50s don't alter the flight path at all until the wing is broken. Tested on right wing of Fw190D9 and Bf109G14

 

Tested same scenario with 20mm on P38 to ensure the AI wasn't on rails and that the recording wasn't bugged. With 1 20mm hit, the flight path is altered and the AI uses ailerons to maintain straight flight. See 2:00 mark

 

.50s CAN kill pilots and damage critical systems, but have no actual effect on the FM unless they break off an entire wing, flap, control surface, or landing gear door. Holes in the wings have no effect

 

@EwokSithLord

 

Awesome, finally some evidence. Thanks for performing this, by any chance do you have TacView? we could really do with seeing if the speed of the aircraft was recorded as changing over time/distance.

 

My concern is that (from my experience) as a player offline and online, I visibly notice the effects of being hit in the wings when flying the Bf 109 and its been my preferred mount for a very long time. I know a briefly hit wing can be manageable if its only a couple of .50 calibre hits or the hits are spread out, but if hit many times in concentration by an accurate burst it will prevent me carrying out tight maneuvers. It does hamper pulling turns and requires a lot of compensation from the pilot when an accurate burst is delivered.

 

I know there is an effect on the FM even if the AI doesn't show it well, it has caused me to be shot down a number of times when trying to evade fighters - especially by players flying P-38's which are very good at getting in an accurate burst at range which usually prevents me escaping and funnily enough also leads to me being overtaken by them. I'm sure most people who fly the '109 regularly will tell you there is an effect on the FM - its just nowhere near as disruptive or as catastrophic as with being hit by HE weapons. There is no world where you can exactly equate the effects of AP and HE other than some theoretical / statistical approximation, they are just different effects - please accept that.

 

.50 calibre AP rounds do not create a blast effect which a pilot would need to compensate for using heavy aileron deflection (some aileron perhaps to adjust), a HE round would however would cause this and an immediate need for correction because of the HE shock effect.

 

One thing to note, if the test setup is a single mission with way-points, the AI will likely be maintaining a set speed and will try to maintain it using engine power - i.e. it automatically compensates to maintain course and speed (it is AI after all).

 

Its interesting that at 0:21 and then several points afterwards the Fw190 D-9 you're firing at changes throttle / power output.. you can hear the engine and supercharger tone change several times which to me suspects the AI is compensating for the damage taken. The same applies to the Bf 109. I could be wrong (no one is perfect) but it certainly raises that question in my mind. The AI will continue to ignore being shot at and simply compensate using throttle changes and tiny control inputs as long as the damage is limited and manageable and the AI is set only to follow objectives/waypoints.

Edited July 22, 2020 by Aurora_Stealth

[unreasonable]

7 hours ago, EwokSithLord said:

 

.50s CAN kill pilots and damage critical systems, but have no actual effect on the FM unless they break off an entire wing, flap, control surface, or landing gear door. Holes in the wings have no effect

 

 

This is provably false. You have essentially repeated much the same test as Nazgul's, in which most of the hits are on flap and aileron. The second level of surface damage, which you do not get as far as I can see, produces a high lift/drag penalty with a noticeable fall off in speed at a fixed engine setting - just as there was right at the end of his test. It is only the first level of surface damage that appears to create no lift/drag penalty.

 

To see if there is a drag/lift penalty you have to be in the the player plane so that you can see what engine settings are required to maintain speed and altitude, or set up a mission in the ME in which the target plane does not have excess engine power to maintain it's waypoint speed. 

 

 

   

[unreasonable]

And here is the proof. The mission has two He111s flying towards a WP as fast as they can. Fire at one - the other is the control.There are two versions, one with the player as a P-51, the other an A-20 so that you can use the upper .50 cal and be 100% sure you do not hit an engine, which is a bit harder in the stang. If you use the A-20 version the He111s are above and quite close - the plane will start in auto level on the same heading so just use throttle to get the target where you want in the sights.

 

You need the Kuban map. 50 cal vs He111 test.zip   50 cal vs He111 test A20.zip

 

Here are screenshots from the A-20 version.  The initial position before I moved the A-20: the Hes are side by side. Second shot is after one burst into outer wing in the area of the cross. You can see that the target plane has immediately fallen behind. The last is ten seconds or so later. That is the effect of one burst of .50 cal from one gun onto one or two wing hit boxes.

 

  

 

 

From the P-51 version: first the matched speeds before firing, second the effect of the damage on the outer wing after one burst, third matched speed with the damaged He111 that has fallen behind. 

 

Edited July 22, 2020 by unreasonable

[Talon_]

10 hours ago, EwokSithLord said:

I used some mission-builder missions to test the effect of .50 AP on the FM by shooting at the right wing of a 190D and Bf109G14 with the P38J

 

 

US .50 AP has no effect at all on the flight model. After around 40 hits to the right wing, the wing breaks off. The plane does not require any control surface deflection to maintain straight flight. .50s don't alter the flight path at all until the wing is broken. Tested on right wing of Fw190D9 and Bf109G14

 

Tested same scenario with 20mm on P38 to ensure the AI wasn't on rails and that the recording wasn't bugged. With 1 20mm hit, the flight path is altered and the AI uses ailerons to maintain straight flight. See 2:00 mark

 

.50s CAN kill pilots and damage critical systems, but have no actual effect on the FM unless they break off an entire wing, flap, control surface, or landing gear door. Holes in the wings have no effect

 

 

 

 

Repeat this test with German 13mm and watch as you crit wings on the first hit too.

[EwokSithLord]

2 hours ago, unreasonable said:

 

This is provably false. You have essentially repeated much the same test as Nazgul's, in which most of the hits are on flap and aileron. The second level of surface damage, which you do not get as far as I can see, produces a high lift/drag penalty with a noticeable fall off in speed at a fixed engine setting - just as there was right at the end of his test. It is only the first level of surface damage that appears to create no lift/drag penalty.

 

To see if there is a drag/lift penalty you have to be in the the player plane so that you can see what engine settings are required to maintain speed and altitude, or set up a mission in the ME in which the target plane does not have excess engine power to maintain it's waypoint speed. 

 

 

   

 

Ok? So 40 .50 cals into the wing arent enough to trigger the second level of damage and have a noticeable effect on flight performance? I suppose a good player should easily get bursts of 100+ rounds into the same wing ? Git gud

 

 

.50s should easily pentrate flap, and edge on hits should have the most impact, not none at all. See the shot up GA wing picture floating around here for example.

 

As for the evidence post, on discord some players mentioned .50 DOES have an effect, its just roughly 60x .50AP = 1x 13mm HE. Over time this may have a measureable effect, but not even remotely significant.

 

AI in my scenario doesn't even notice, and they're using same FM as player. AI does notice the 20mm, and not just the initial shock either, so its not an AI FM bug.

 

There is something very obviously wrong, I don't see why people are trying so hard to say it's just fine or realistic.

[Talon_]

1 minute ago, EwokSithLord said:

There is something very obviously wrong, I don't see why people are trying so hard to say it's just fine or realistic.

 

Do some direct comparisons, 13mm vs 50cal. Shoot both nations with both guns (.50 vs 109/190/Mustang, 13mm vs 109/190/Mustang) and you'll put an end to this madness.

[unreasonable]

1 hour ago, EwokSithLord said:

 

Ok? So 40 .50 cals into the wing arent enough to trigger the second level of damage and have a noticeable effect on flight performance? I suppose a good player should easily get bursts of 100+ rounds into the same wing ? Git gud

 

 

.50s should easily pentrate flap, and edge on hits should have the most impact, not none at all. See the shot up GA wing picture floating around here for example.

 

As for the evidence post, on discord some players mentioned .50 DOES have an effect, its just roughly 60x .50AP = 1x 13mm HE. Over time this may have a measureable effect, but not even remotely significant.

 

AI in my scenario doesn't even notice, and they're using same FM as player. AI does notice the 20mm, and not just the initial shock either, so its not an AI FM bug.

 

There is something very obviously wrong, I don't see why people are trying so hard to say it's just fine or realistic.

 

It is not a matter of saying that it is just fine or realistic, it is a matter of getting your facts right.

 

.50 cals can and do create lift/drag penalties in the game - in the case of the He111 one box was enough.  The P-51 case was one 160 round burst - about 2 seconds, not all of which hit, which got level 2 damage over much of the wing, causing the target to drop out of formation immediately. 

 

Whether the number currently required is realistic is a matter of opinion.  The GA pictures show fire damage - the ammunition was probably a modern explosive/incendiary round, so that is  very misleading. Perhaps there is a reason why the USAAF liked to mount it's  .50 cals six per plane on P-51s and 47s?  

 

On the issues of hits to aileron and flap not passing through, and the relative effectiveness of 13mm HE you may have a point. The first just seems to be a limitation of the DM which will usually not matter since most shots in combat are actually at an angle. I have not tested the 13mm myself so express no view.   

 

I would think that the best way to test how many hits are required to get to stage 2 damage is best done in a static ground test firing from the A-20's top turret. Then you can aim at specific wing hit boxes at close range and actually count the hits.  

Edited July 22, 2020 by unreasonable

[BCI-Nazgul]

3 hours ago, Talon_ said:

 

Do some direct comparisons, 13mm vs 50cal. Shoot both nations with both guns (.50 vs 109/190/Mustang, 13mm vs 109/190/Mustang) and you'll put an end to this madness.

We already did this test.  The 131 is FAR more damaging.  An entire load of US .50 from a P-39 into one wing did less damage than 1 short burst of 131.  Same number of guns drastically different results.

[Caudron431]

1 hour ago, BCI-Nazgul said:

We already did this test.  The 131 is FAR more damaging.  An entire load of US .50 from a P-39 into one wing did less damage than 1 short burst of 131.  Same number of guns drastically different results.

That could be because the blast area of high  explosive ammo can reach and trigger the wing DM boxes while on the other hand the .50cal is stopped by the flaps and ailerons "shield" in the test.

 

Another limitation of the DM could be the size of the blast area for HE 13 and 12.7mm HE ammo which could possibly be more important than real figures explaining the (too important?) differences between AP and HE in the game.

Perhaps all HE ammo have a similar blast area explaining why MG HE ammo damage is looking much more like cannons shell damage than to AP rounds for the same caliber.

Then the problem would not be the .50cal modelling but the HMG HE ammo one.

 

Just speculating. This thread is very interesting.

3 hours ago, unreasonable said:

On the issues of hits to aileron and flap not passing through, and the relative effectiveness of 13mm HE you may have a point. The first just seems to be a limitation of the DM which will usually not matter since most shots in combat are actually at an angle.

 

Sometimes,  you can also have a situation when an aircraft is running away on the deck, in this situation would'nt the running pilot have an important advantage due to this DM limitation because then the DM area would be very small.

In other cases you are absolutely right of course, and the .50 cal are far from being weak anyway, well used even with these limitations they are a very potent weapon, and it may become even more deadly with the new fuel system modelling that is coming.

Edited July 22, 2020 by Caudron431Rafale

[JG13_opcode]

14 hours ago, BCI-Nazgul said:

I've read many theories about why this is happening:  DM not complicated enough, network/netcode issues, no API, M2 pilots can't aim, etc... but the fact remains that M2 armed planes are flying have been flying around with one-hand tied behind their back (online at least) for months.  I'd happily trade 6 - 8 M2's in for a couple 131's or 12.7 mm's right now.

 

It's probably a combination of all those factors.  Certainly, lots of people overestimate their gunnery skill.  I had a guy online go insane a few mins ago on Combat Box because he "shot the f*ck" out of me and yet I still turned the tables and put a 30mm into his canopy.  After reviewing the sortie log it showed he hit me just 14 times (which is less than 2 hits per gun on his P-47) and most of those hits were to the wings.

 

Anecdotally, the 50 cals CAN do significant damage if you hit the engine cowling or the canopy.  I have footage to prove it, but they're a difficult weapon to use if you're looking for kills as opposed to just rendering the other guy combat ineffective.

[BCI-Nazgul]

1 hour ago, Caudron431Rafale said:

That could be because the blast area of high  explosive ammo can reach and trigger the wing DM boxes while on the other hand the .50cal is stopped by the flaps and ailerons "shield" in the test.

Flaps and ailerons "shield"?   I'm not sure what you exactly mean by this.  If you mean that maybe there is a bug that causes only flap and aileron hits when firing .50 cal at a wing I could buy that.   If you mean that US flyers are such awesome shots that we can put our rounds only into the flaps and ailerons I'm going to call BS on that line of reasoning.  .50 cal rounds should hit all over the wing no matter what angle and distance they're fired from.  No one is good enough to only hit the control surfaces unless they're shooting at stationary targets from stationary planes aka gun turrets from point blank range.  I'm just happy when I hit anywhere on the target in a dogfight.  Unfortunately, in a .50 armed plane that pretty much means nothing unless you're lucky.  As a reference my friend took up a 109 and shot down 6 enemy in one sortie online.  The same guy using US .50 armed plane (P-51) is lucky to manage one kill per sortie.   This is not a skill problem, it's a weapon performance issue.  From my experience the only way to be certain to get a kill with .50s online is to have a nice cooperative enemy pilot let you put well aimed full 1 sec (or more) burst into their plane at less then 250 meters.  That means no dodging by the enemy just a sitting duck.  Any other kills with .50s are pretty much luck (engine/pilot/fire.)  While the Russian and German pilots only need to put one round from any weapon into you to immediately make your plane unfightable then they just have to finish you off at their leisure.

Edited July 22, 2020 by BCI-Nazgul

[BCI-Nazgul]

18 minutes ago, JG13_opcode said:

 

It's probably a combination of all those factors.  Certainly, lots of people overestimate their gunnery skill.  I had a guy online go insane a few mins ago on Combat Box because he "shot the f*ck" out of me and yet I still turned the tables and put a 30mm into his canopy.  After reviewing the sortie log it showed he hit me just 14 times (which is less than 2 hits per gun on his P-47) and most of those hits were to the wings.

 

Anecdotally, the 50 cals CAN do significant damage if you hit the engine cowling or the canopy.  I have footage to prove it, but they're a difficult weapon to use if you're looking for kills as opposed to just rendering the other guy combat ineffective.

Don't you think you're plane would have been pretty unfightable after 14 hits?  That is close to historical average to shoot down an enemy plane with .50s.  From my reading the average was 14 - 20 hits average.  Sure engine and cockpit would be better, but there is plenty of important stuff in the wings of fighter planes.

 

That reminds me of another "problem" we've noticed in our tests.   None of wing hits resulted in any critical hits.  No guns broken, no jammed flaps or ailerons, no ammo explosions, nada... that is possibly a big problem with the current DM at least as far as .50s are concerned.

Edited July 22, 2020 by BCI-Nazgul

[JG13_opcode]

39 minutes ago, BCI-Nazgul said:

Don't you think you're plane would have been pretty unfightable after 14 hits? 

 

Not really.  I've put multiple 151/20 hits into the wings of e.g. an IL2 before, and it kept flying.  A .50 BMG ought to just punch through the wing skin unless it hits a spar or something else on the way through.  As it was, I was fighting to keep the aircraft from spinning out the whole time and it was definitely a hairy fight, so let's not pretend I was flying unscathed.

 

The point of that example was to illustrate that the guy did not aim successfully and instead was spraying wildly and got a bunch of wing hits.  After 14 hits to the engine cowling or the canopy I'm sure I would have been instantly killed/disabled.

39 minutes ago, BCI-Nazgul said:

From my reading the average was 14 - 20 hits average

 

Where can I read about this?

Edited July 22, 2020 by JG13_opcode

[BCI-Nazgul]

1 hour ago, JG13_opcode said:

 

Not really.  I've but multiple 151/20 hits into the wings of e.g. an IL2 before, and it kept flying.  A .50 BMG ought to just punch through the wing skin unless it hits a spar or something else on the way through.  As it was, I was fighting to keep the aircraft from spinning out the whole time and it was definitely a hairy fight, so let's not pretend I was flying unscathed.

 

The point of that example was to illustrate that the guy did not aim successfully and instead was spraying wildly and got a bunch of wing hits.  After 14 hits to the engine cowling or the canopy I'm sure I would have been instantly killed/disabled.

 

Where can I read about this?

I'll try to find that info.  It's been a long time since I read it.  Years actually, but obviously it's stuck in my mind.  It could be in a book I read even which means it may not be possible to easily find it.

 

Found something interesting, but not conclusive:  https://apps.dtic.mil/dtic/tr/fulltext/u2/a179871.pdf

 

From that article on page 4: "The German aerial combat experiences during World War II illustrate the relationship of caliber to firepower. Their problem in aerial combat differed from that of the Allies because their targets included both thick-skinned B-17 bombers and Allied fighters. In that environment, a high probability of hit does not equate to a corresponding high probability of kill unless the bullet is of sufficient size to do damage. German experience showed that it took 50-100 hits with 12.7mm (.50 in.) projectiles to down a B-17. By way of comparison, they obtained similar results from only 18-20 hits with 20mm high explosive (HE) projectiles, or four hits with 30mm HE projectiles. (15:44) Not surprisingly, the Germans believed that the problem resolved itself into developing an aerial gun of the largest caliber within the weight constraints of the aircraft. They considered 30mm adequate for air-to-air work and, consequently, built several 30mm guns. Among these was the Mauser MG-213C, which had a rate of fire of 1500 r.p.m. (15:45) U.S. forces later captured an MG-213C intact and U.S. gun experts eagerly exploited the weapon. (16:37)"

 

Maybe you can extrapolate down that if it took 50 to 100 hits to down a four engine bomber a single engine fighter would require 12.5 - 25 hits.   That's pretty much what I remembered, but this is not the same article or reading I did and of course, that is the German .50 no doubt they were discussing. 

 

From the same article's bibliography this would be something interesting to read, but it is unpublished:

 

Unpublished Sources 38.

 

Lisecki, John R., Maj. "The Caliber . 50 Machine Gun and Fighter Aircraft." Research Study prepared at the Air Command and Staff College, Air University, Maxwell AFB, Ala, December 1949.

 

Edited July 22, 2020 by BCI-Nazgul

[Caudron431]

46 minutes ago, BCI-Nazgul said:

If you mean that maybe there is a bug that causes only flap and aileron hits when firing .50 cal at a wing I could buy that. 

Exactly what i meant. At those angles when you are directly on the target's six and shooting at the wings. The HE ammo only hit the ailerons and flaps kinetically and would not do anything to the wing  but chemically their blast is large enough (perhaps too large i don't know) to reach the wings DM boxes and cause damage similar to 20mm HE round.  The issue is as Unreasonable said related to limitation in the DM programming. But we have to remember that it is always a work in progress, and we can all remember that the situation was reversed not so long ago when the Minen 20mm were clearly underpowered. I'm no specialist at all, i really don't know about this, all i can do is speculate, but i'm sure if there is something wrong the team will look into it, just like they did for the Minengeschoss.

 

1 hour ago, BCI-Nazgul said:

The same guy using US .50 armed plane (P-51) is lucky to manage one kill per sortie.   This is not a skill problem, it's a weapon performance issue.  From my experience the only way to be certain to get a kill with .50s online is to have a nice cooperative enemy pilot let you put well aimed full 1 sec (or more) burst into their plane at less then 250 meters. 

 

Don't forget that online has also shown problems due to connection and data transfer. Frankly i am one that believe that this thread is legitimate and that there are questions about the DM. Look at the second part of my last post.

 

But that said, i don't believe the 50s are so far off, i still find them very effective. The drag question deserves to be put and explored. That said the weapons are different and require different point of view to use them effectively, they require specialization and practice especially when you initially don't like them, just because you are good with one doesn't mean you are goingt to be as good with another one.

 

 

 

 

[unreasonable]

Using the US Ballistics lab assessment of 50 cal API-T, with a probability of downing a P-47 from each hit of 0.037, then after 14 hits at a bunch of P-47's you would have shot down about half of them.  1-0.037 =  0.963    0.963^18=   0.507   So a range of 14-20 is in agreement.

 

This, however, if for A kills+B kills, which include planes that take up to 30 minutes to go down (B kills).  To get the equivalent for A kills only (less than 5 minutes) use 0.017    0.983^40 = 0.504

 

These numbers are also for random hits anywhere on the plane - almost all the kills would be due to damage to engine, pilot or fuel systems.  A+B Kill damage for structures is rated at 0.011 -  0.989^62 = 0.504   So to A or B kill a P-47, with hits none of which damage engine, fuel or pilot, you need an average of 62!

 

This is why using an average number when you are only firing at the wing is invalid.

 

The German numbers for heavy bombers reflect what they thought was needed to get hits that started fires, put out engines or disabled pilots.

 

 

 

 

[unreasonable]

5 hours ago, BCI-Nazgul said:

.  Any other kills with .50s are pretty much luck (engine/pilot/fire.)  While the Russian and German pilots only need to put one round from any weapon into you to immediately make your plane unfightable then they just have to finish you off at their leisure.

 

And that is exactly why everyone switched to cannons as soon as they were capable of producing them in large numbers to specs that made them work. Something the US notably had difficulty with, which is beyond the scope of the thread.  By far the most vulnerable part of a target to 50 cal hits is indeed the pilot. In contrast they were poor against structures. This is the view of the US government's own Ballistics Research Laboratory.  

 

It is a similar problem that the RAF faced in the BoB with planes armed with 8 .303s.  You had to absolutely riddle a target with bullets or get lucky.   While 50 cals are better than 303s this is just a matter of degree, not of kind. They are mostly better in penetrating and damaging the parts you need to hit - pilot, engine, fuel systems. 

Edited July 23, 2020 by unreasonable

[JG13_opcode]

5 hours ago, BCI-Nazgul said:

Maybe you can extrapolate down that if it took 50 to 100 hits to down a four engine bomber a single engine fighter would require 12.5 - 25 hits.   That's pretty much what I remembered, but this is not the same article or reading I did and of course, that is the German .50 no doubt they were discussing. 

 

Look I'm sympathetic to the idea that there is something wrong with the M2 50 cal, but you can't just divide by the number of engines.  That's not scientifically rigorous, and I would argue the chances of "average number of hits to bring down the aircraft" is very unlikely to be linearly correlated with the number of engines.

[BCI-Nazgul]

3 hours ago, unreasonable said:

Using the US Ballistics lab assessment of 50 cal API-T, with a probability of downing a P-47 from each hit of 0.037, then after 14 hits at a bunch of P-47's you would have shot down about half of them.  1-0.037 =  0.963    0.963^18=   0.507   So a range of 14-20 is in agreement.

 

This, however, if for A kills+B kills, which include planes that take up to 30 minutes to go down (B kills).  To get the equivalent for A kills only (less than 5 minutes) use 0.017    0.983^40 = 0.504

 

These numbers are also for random hits anywhere on the plane - almost all the kills would be due to damage to engine, pilot or fuel systems.  A+B Kill damage for structures is rated at 0.011 -  0.989^62 = 0.504   So to A or B kill a P-47, with hits none of which damage engine, fuel or pilot, you need an average of 62!

 

This is why using an average number when you are only firing at the wing is invalid.

 

The German numbers for heavy bombers reflect what they thought was needed to get hits that started fires, put out engines or disabled pilots.

 

 

 

 

Sorry, my last couple posts were concerning the effectiveness of the .50 in general in my experience, so it got a little off topic from the main post.  It could well take more if only wing hits.  All on the same wing would probably yield different results than 7 on each as well.  However, your calculated numbers do line up with my memory and the pretty much with article I found.   

Edited July 23, 2020 by BCI-Nazgul

[unreasonable]

In general the size and location of pilots is pretty well modelled as is the armour, so the chances of getting a hit on a pilot if you hit the aircraft should be fairly accurately rendered in the game, although perhaps in the game the player in particular maintains control after a hit that is not immediately fatal better than a real pilot could do.   If the overall effectiveness is very badly out,  it should be possible to determine this from tests using ground fire - there is a .50 cal AAMG IIRC, which could be used to get fairly random hits from a variety of angles in an offline test similar to the one I did years ago for the 20mm HE LAA, which could be compared to the US test results.

 

It is a lot of work and I do not feel inclined to do it at least until the developers announce that they have completed the current sweep of the DM including any fuel and incendiary changes they plan.

 

 

[BCI-Nazgul]

2 hours ago, JG13_opcode said:

 

Look I'm sympathetic to the idea that there is something wrong with the M2 50 cal, but you can't just divide by the number of engines.  That's not scientifically rigorous, and I would argue the chances of "average number of hits to bring down the aircraft" is very unlikely to be linearly correlated with the number of engines.

It's not rigorous as far as an actual study for .50s shooting at German planes true enough.  I don't even know if the Allies ever did that kind of study themselves.  The study Unreasonable posted was done using intact US planes as targets under controlled conditions.  You'd have to be able to find a large number of downed German fighters (some of which were reduced to small pieces) and count the bullet holes somehow or have a large number of intact captured German fighters to use as targets.   That seems completely impossible in the middle of a war.   But I do find it interesting that Unreasonable's calculation above, my memory and the extrapolation from the paper I quoted all seem to line up within 10%.  Sometimes the only practical approach is to use complied historical statistics not actual studies, but that will work pretty accurately given a large enough number of cases to look at.   My guess is that there probably is a statistical relationship of some kind, but I'm not going to spend the time to try to do all that research and math.

[BCI-Nazgul]

11 minutes ago, unreasonable said:

In general the size and location of pilots is pretty well modelled as is the armour, so the chances of getting a hit on a pilot if you hit the aircraft should be fairly accurately rendered in the game, although perhaps in the game the player in particular maintains control after a hit that is not immediately fatal better than a real pilot could do.   If the overall effectiveness is very badly out,  it should be possible to determine this from tests using ground fire - there is a .50 cal AAMG IIRC, which could be used to get fairly random hits from a variety of angles in an offline test similar to the one I did years ago for the 20mm HE LAA, which could be compared to the US test results.

 

It is a lot of work and I do not feel inclined to do it at least until the developers announce that they have completed the current sweep of the DM including any fuel and incendiary changes they plan.

From the article: "During World War II, all USAAF fighters carried multiple M-2 weapons and, therefore, packed sufficient firepower to destroy enemy fighter aircraft. The M-2's inability to fire an explosive round did not pose a significant problem as fighter aircraft generally had thin skins and contained flammable aviation fuel. Consequently, a P-47, carrying eight .50 caliber guns, had a high probability of hit because its total rate of fire was 6000-6800 rounds per minute (r.p.m.). This, in turn, yielded a corresponding high probability of kill. Even though the M-2 performed well in World War II. gun experts realized that its shortcomings would limit its future effectiveness. The USAAF had compensated for the M-2°s major limitation, a low rate of fire, by employing multiple guns on fighter aircraft. However, aircraft developments late in World War II sealed the fate of the M-2."

 

I'm hoping that the fuel and incendiary DM upgrades will make a difference.   That does line up with the authors statement above "and contained flammable aviation fuel."  My feeling right now is that MG HE tipped rounds are too effective and need to be reduced.  One thing that I realized today is that an AP round will make two .50 holes in a wing while .50 HE if it detonated correctly would make one larger hole.   Given the tiny charge these rounds had it doesn't seem as likely that the aero damage would be that much different.  Does anyone have WWII pictures of US planes damaged by 131 fire and pictures of German planes with M2 hits?   That might be enlightening.

[SAS_Storebror]

I'm sure this one has been linked before and I'm quite confident that experts - self-proclaimed and real ones - have torn it to pieces before, nevertheless I kinda like these comprehensive gun effectivity comparison tables and find that the approach and the conclusions sound quite reasonable.

They just don't match what we witness ingame, particularly concerning the cal .50s, but that's not really a surprise is it?

 

http://www.quarryhs.co.uk/WW2guneffect.htm

 

Mike

[sevenless]

7 hours ago, BCI-Nazgul said:

I'm hoping that the fuel and incendiary DM upgrades will make a difference.   That does line up with the authors statement above "and contained flammable aviation fuel."  

 

Not only the fuel tank. Also the ammo boxes. See my post here:

 

 

[Aurora_Stealth]

1 hour ago, SAS_Storebror said:

I'm sure this one has been linked before and I'm quite confident that experts - self-proclaimed and real ones - have torn it to pieces before, nevertheless I kinda like these comprehensive gun effectivity comparison tables and find that the approach and the conclusions sound quite reasonable.

They just don't match what we witness ingame, particularly concerning the cal .50s, but that's not really a surprise is it?

 

http://www.quarryhs.co.uk/WW2guneffect.htm

 

Mike

 

It's a really nice article, seen it a few times over the years but it's great to read through the details again.

 

Would be good if we could see how a MG 131 (13x64B) API round would stack-up against the (shown) .50 calibre API (12.7x99). Unfortunately the former is missing from the first table.

 

The intermediate AP / HE round shown for the MG 131 seems neither here nor there, but then again if the Luftwaffe was mixing belts with both the AP/HE and API types it begins to makes more sense.

 

Only reinforces what was already thought, we need API rounds implemented for all the relevant guns (WIP) and then a round up of where things stand comparatively and tweak from there. It may well be that certain guns are under or over-performing in-game but we will need the correct ammunition available to make a straight comparison in-game with what's in that table.

 

Cheers,

Edited July 23, 2020 by Aurora_Stealth