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Wing Leader: Victories 1940-1942» Forums » General

Subject: Firepower difference: Zero vs Wildcat rss

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ADDA Marc
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I just played Cactus Thorn (IIRC), where A6M2 vs fighting Wildcats. I was surprised to see that the former have a firepower of 1, armed with 20 cannons and some light MGs, whilst the latter have a firepower of two but carrying 6 cal 50 (funny, I thought it was only 4 x .50 but it seems they had 6).
Wouldn't it have been the opposite? or at least the same FP of 2?
Note that I didn't tried to compare all ADC between them. And maybe I should have.

Marc
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Lee Brimmicombe-Wood
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I'm away from home at the moment, but when I get back I'll be happy to post my tables used to generate the Firepower values. They are derived from the formulae used by Williams and Gustin, part of which is explained here:

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

http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-pe.html

Basically, from these numbers I derived a table of total effective firepower from which the Firepower values are derived. Now, these have been subject to some adjustment by me. For example, I felt there needed to be a difference between four fifty cals and six of them, so the boundary sits between the two. (However, by setting the boundary at this point it means there's no effective difference in the game between six .50s and eight. This is fine because while the historical narratives draw a distinction between the firepower of four and six .50s, there's nary a word said on the difference between six and eight.)

I find this works for my purposes. Yes, there are 'cellophane' boundaries between the levels and some weapon loadouts sit uneasily near these boundaries, but as a system it seems to be delivering the outputs I want. It highlights the gradual improvement towards ever-higher firepower, while aircraft protection advanced very little after the first year of the war.
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ADDA Marc
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Very interesting. I don't thank you for all the time I will spend on reading this very interesting site.

Marc
 
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Lee Brimmicombe-Wood
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For what it's worth the firepower values in the Williams and Gustin book, when totalled, can be referenced on this firepower table to give you the scores in the game.

Game FP = Total Firepower

0 = 0 - 100
1 = 100 - 300
2 = 300 - 700
3 = 700 - 1500
4 = 1500 - 2500
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Lee Brimmicombe-Wood
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This is Williams and Gustin's book on the fling guns of WW II. Highly recommended. As you can see I pretty much plug their gun effectiveness data into my game.

https://www.amazon.co.uk/d/Books/Flying-Guns-World-Anthony-W...
 
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Tom T
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The early F4F-3 had only four 50-cal MGs. The F4F-4 had six.

The Zero had two 30-cal MGs and two 20-mm cannons.

A lot of factors go into the gunnery effectiveness of these two aircraft. The 20-mm cannons had a slower rate of fire than the 50-cals. And a much lower muzzle velocity. A higher MV means the bullets fly straighter (more accurately).

20mm

Rate of fire: 520 rounds/min
Muzzle velocity: 600 m/s (1970 ft/s)

50cal

Rate of fire: 600 rounds/min
Muzzle velocity: 840 m/s (1970 ft/s)

So, in a few second burst the six 50s would deliver more rounds and at a higher velocity (more accurately) than the two 20mms.

Dogfighting accuracy also depended on how stable the aircraft was as a gun platform among many other factors.

Tendency to jam was another factor. A friend of my flew a B-25H with 8 forward firing 50cals. in the Pacific. His bomber wing attacked Japanese bases in the South Pacific. He said the 50s frequently jamming. They had cables they yanked in the cockpit to recharge them when they did. He said that they would be flying in on a strafing run when he'd notice that only one or two of the guns were actually firing. He and the copilot would be feverishly yanking the cables as they were on the run.

If a Japanese pilot loses his two 20s to jams, he's in big trouble. If the American pilot loses two 50s to jams, he's got four more.

That's an over simple comparison, but you get the point.

 
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Lee Brimmicombe-Wood
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There’s a number of different ways you can do the math on firepower. I choose the Williams and Gustin method because it is a good off-the-shelf solution that takes in factors such as rate of fire, weight of fire and explosive power. I admit my method doesn’t go into detail of jam rates or even battery layout, but then as you can see from the table above it’s quite crude when you get to it. There's not a lot of space for subtlety.

It was interesting to me that the reason the F4F-4 had six .50s was because the Royal Navy, which by this time had some experience of combat, assessed the F4F-3 as being under-gunned. It’s also interesting that the Americans generally settled on six or eight .50s for many of their aircraft because they were mostly taking on either fighters, or less well-protected Japanese bombers. The British move to 20mm cannon was a decision taken earlier in the war when one of their prime requirements was air defence against bombers.

So factors like this this tend to determine the break points in my table. One between four and six fifty cals and one between two and four 20mms.
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Joseph Youren
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I won't pretend to have the in-depth knowledge Lee uses when making game decisions but for me the difference is small-arms rifle ammunition vs. heavy machine gun ammunition. Fire a .30 calibre round into the engine block of a junker auto somewhere on a dirt road in the middle of nowhere. whistle Try to find the damage. Do the same with a .50 cal. Compare. 20mm cannon pack a whallop but rate of fire compared to multiple .50 cal MGs means hundreds more opportunities for heavy damage.
 
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Lee Brimmicombe-Wood
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It doesn't quite work like that. Williams and Gustin give you the inside story on this, but the Americans, British and Germans all did studies on weapon effectiveness and aircraft survival. The Americans, for example, discovered that very few losses were due to destruction of aircraft structure. Most were due to hits on vulnerable systems, such as the oil system, fuel and, of course, the pilot. This was why most efforts at armouring aircraft tended to be focused on these areas.

The other thing they found was that aircraft were largely empty spaces. In the Battle of Britain the Germans discovered that their bombers, which benefited from the redundancy of multiple engines, could withstand lots of hits from rifle-calibre rounds; even from eight-gun Spits and Hurricanes. It became clear that if you wanted a better chance of hitting something vital on a bomber then a bursting round was necessary. And that these would deliver far more hitting power, despite the lower rate of fire.

This was why the Germans moved towards ever-heavier calibres, finding that a low muzzle-velocity 30mm bursting round could take a B-17 down with just a handful of hits, and would probably disintegrate a smaller aircraft with a single hit.

The British found their ideal balance with the 20mm Hispano--good enough against both fighters and bombers, as well as ground targets, while trading off the weight of the gun battery. However, the Americans found themselves taking on much lighter opposition--mainly interceptors and lightly-protected Japanese bombers. They felt their .50 cals were plenty for dealing with these problems, without a prohibitive weight penalty.
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