(yet) another AH fighter firepower comparison

[Anaxogoras]

What's the justification for assuming that the hangar data (standardized kinetic/chemical damage) is closer to the AH guns' damage against planes than Williams' formula?

Simply the fact that it's within-game.  There's a reason why we test things in the game instead of looking in books for performance data.

[Lusche]

Simply the fact that it's within-game.  There's a reason why we test things in the game instead of looking in books for performance data.

Yes, and that's what i will always prefer. But you have to admit that this test is also somewhat comparing apples and oranges. Shooting at structures is not the same as shooting against planes. It's modeled differently (massively simplified), so we can't be sure our findings are completely valid vs. planes.

And that's why I titled this thread "another comparison" and did put a huge disclaimer in my OP. I'm simply presenting a different approach.

6. This table isn't meant to replace the gun comparison table on the Training Corps website.  The numbers here are are real world values. The values on the AHTC page show the destructive power of a single round vs objects in Aces High and are tested & verified withing the game. Both tables can give you different results.

[Lusche]

One example that may perhaps be of interest:

damage vs structure:

37mm NS-37 = 17.15lbs
37mm M4 = 17.1lbs

Almost the same.

I really hope both rounds do not the same damage to planes because:

NS-37   projectile mass 735g, velocity 900m/c, HEI contend 6%
M4 projectile mass 608g, velocity 610m/s, HEI contend 7.4%

Both rounds carry about the same amount of HEI filling, but the NS-37 shell has 273% higher kinetical energy and 78% greater momentum (which Mr. Williams used for his computations in place of energy) than the M-4.

[druski85]

One example that may perhaps be of interest:

damage vs structure:

37mm NS-37 = 17.15lbs
37mm M4 = 17.1lbs

Almost the same.

I really hope both rounds do not the same damage to planes because:

NS-37   projectile mass 735g, velocity 900m/c, HEI contend 6%
M4 projectile mass 608g, velocity 610m/s, HEI contend 7.4%

Both rounds carry about the same amount of HEI filling, but the NS-37 shell has 273% higher kinetical energy and 78% greater momentum (which Mr. Williams used for his computations in place of energy) than the M-4.

I'm glad you brought this up.  This was without a doubt the most surprising aspect of this whole chart for me.  424 damage for a Russian 37 mm, 160 for an American?  That is less damage than a Hispano V round.  Is that a typo, or were the M4 rounds really that weak?  I seem to bust planes apart with the 39 in game...

[Lusche]

I'm glad you brought this up.  This was without a doubt the most surprising aspect of this whole chart for me.  424 damage for a Russian 37 mm, 160 for an American?  That is less damage than a Hispano V round.  Is that a typo, or were the M4 rounds really that weak?  I seem to bust planes apart with the 39 in game...

A great factor is the low ROF. Thhe M4 has a ROF of only 2.5. But even while being a comparatively weak round for its caliber, it  is still strong enough to kill any fighter with one hit.

"Cartidge Power": Hispano 20, Mk 108 58, M4 64, NS-37 106

[Lusche]

For comparison:

This is a chart based on "Firepower vs structures"



Methodology:
Damage values for the rounds were taken from the AHTC site. When those were missing I tested the round the following way: offline mode, hangar set to hardness 2.0. Shoot at hangar, note how many rounds it took to kill the FH. Damage value = 2000lbs/#rounds.

Weapon  ROF's tested by me. Ammo capacity set to 10. Set timer, pull primary or secondary trigger for 20 seconds. Divide divide number of rounds used by 20.

[moot]

Simply the fact that it's within-game.  There's a reason why we test things in the game instead of looking in books for performance data.

You know that kinetic energy isn't calculated in object impacts, right?

[E25280]

You said this was calculated with the velocity exiting the muzzle. 

It would be interesting to see how the lethality would change at, say, 300 yards when fired from an aircraft flying 300mph.  Deceleration of the rounds would vary based on size and balistic qualities, so I would guess the lethality at range could end up being very different.

[Lusche]

You said this was calculated with the velocity exiting the muzzle. 

It would be interesting to see how the lethality would change at, say, 300 yards when fired from an aircraft flying 300mph.  Deceleration of the rounds would vary based on size and balistic qualities, so I would guess the lethality at range could end up being very different.

I would be able to do that for German guns only, as I don't have sufficent data on other nations weapons.

Three examples:

30mm Mk-108 Minengeschoss

000m - 505m/s - "cartridge power" 58
800m - 225m/s - "catridge power" 49 = 84%


13mm MG131 Brandsprengranate

000m - 750m/s - "cartridge power" 3.8
800m - 294m/s - "cartridge power" 2.27 = 60%

7.92 mm Panzergeschoss

000m - 810m/s - "cartridge power" 0,81
800m - 290m/s - "cartridge power" 0,29 = 36%


As the 30mm round retains its destructive capabilty better because of its explosive charge, which is very small in the MG 131 and non-existent in the 7.92mm round


And before someone complains, these are real-world values

[Krusty]

Bullets vs objects is nowhere near the same as bullets vs aircraft. Aircraft take into account penetrating power, explosive power, many other aspects including internal damage systems of the target itself.

Objects are very flawed, and IMO I think they negate a lot of the round power of MGs, and I think they soak up too much "splash damage" from cannons, but this is only personal guesswork.

Since we don't have HTC's exact numbers (other than saying 1 50cal is worth 3 30cal, 1 hispano worth 3 50cal, etc), and we know that certain relationships seem to match up to the real things, I tend to lean more towards Tony Williams than the flawed "rounds to kill a hangar".

[Anaxogoras]

But what evidence do we have the lethality vs aircraft matches Tony Williams?

[Krusty]

He's been around for ages. There've been a number of threads over the years and general memory is that they seem to mesh with AH numbers they were compared to. Usually folks compare them to him in a positive way.


Generally speaking, most do. Now that I think about it, I don't think I've really seen many that didn't (aside from the whole MG151-averaged-issue and a couple other specifics)

[gripen]

But what evidence do we have the lethality vs aircraft matches Tony Williams?

The lethality is, of course, function of many more factors than simple comparison of projectile energy (mechanical and/or chemical). In other words, one armament combination might have large theoretical advantage on destructive power over another combination. However, in practice other factors, like better probability of hit due to higher velocity of the projectiles, might even out the lethality.

This is rather easy to test in the game; take as example the P-47D and the K-4 (theoretically about equal firepower) and shoot the drones at long range (above 200) with slight deflection. You will find out that the P-47D turns out to be superior in lethality in these conditions.

[moot]

But what evidence do we have the lethality vs aircraft matches Tony Williams?

Plot the Williams and HTC object figures and see for yourself.

[Anaxogoras]

Yes, I've read a lot of his articles, and I like the work that he's done.  But a good reputation and frequent citation is not evidence that his figures match Aces High.  Looking to his work to figure out lethality is comparable to asking how fast the P-47 rolls in the game, and then reading a book about it instead of testing the roll rate yourself in game.  You'll probably learn a lot of interesting things and enrich your historical understanding of the P-47, but come away with a misunderstanding.

I understand that damage against objects takes no account of kinetic energy loss, which is accounted for in damage versus planes.  However, it seems that the most strident debate is generated over auto-cannon lethality, which is mostly chemical energy, kinetic energy only to a lesser extent.  This is where discrepancies exist between the two methods of ranking, i.e. Ki-84 vs Spit8.

Plot the Williams and HTC object figures and see for yourself.

If by this you simply mean that I should compare how well Williams matches the hangar destruction data, it begs the question because that's what we're arguing about in the first place.  Did you mean something else?

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Edit:  I had the thought that maybe you think I'm the one begging the question?  After all, since the Williams chart does match the hangar data in most cases, why am I asking what evidence we have to suppose that it matches the game?  To be clear, I'm asking, why go with Williams for damage vs aircraft where it disagrees with the hangar test data?...especially when the disagreement is over cannon armed aircraft where kinetic energy matters least.