Author Topic: Hard Data for Bullit drop (190 Cannons & F4U cannons) (Read 448 times)

Saintaw · « **on:** May 09, 2000, 02:15:00 AM »

Sorry for my lack of Knowledge, I'd like to see some data for these 2 (NOT A WHINE, I FLY BOTH !)

*Muzzle velocity (Rounds Velocity) ---> I need to know how much time it will take for a Bullit to reach that Con at D.400 in front of me

*Bullet Drop Vs Distances
*Rounds Per minute

Thank you !

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Saw/Saintaw
=XO=II/JG2~Richthofen~
GMT T.O.D. SITE

JG2 "Richthofen"
Don't shoot ! I am only an observer......

[This message has been edited by Saintaw (edited 05-09-2000).]

MANDOBLE · « **Reply #1 on:** May 09, 2000, 03:38:00 AM »

Saintaw, when comparing both weapons we must take into account the round types. For example, most of the HS hits should produce holes, most of the Mg151 hits should produce explosions and fire. So, IMO lethality of the Mg151/20 using the normal loadout of HE and EI rounds should be greater than HS with the normal loadout of AP rounds. The effect of a low kinetick enery 20mm HE round is devastating compared to a hi kinetick energy 20 mm AP round. Just check pictures of B17 parts damaged by those kind of rounds...
As far as I know, most of the 190A8 were using great amounts of HE/EI ammo, while HS aircraft used mostly simply AP rounds.

Check these pages for more data: http://warbirdsresourcegroup.org/LRG/mg151.html http://www.danshistory.com/ww2/guns.html http://web.mountain.net/~arringto/table-leth.htm http://member.nifty.ne.jp/flying_dutchman/reference/guns.html

And this book should have even more data, not yet published though: http://www.users.globalnet.co.uk/~autogun/rfweb.htm

Saintaw · « **Reply #2 on:** May 09, 2000, 03:59:00 AM »

Thx Mando !

BTW, looking at this table WHICH is the 20 MM i Find on the FW190 A8 In Aces High ???

MG c/30L Germany 20mm x 138B ( 119 g ) 350 rpm 900 m/s 64 kg
MG FF Germany 20mm x 80RB ( 115 g ) 520 rpm 570 m/s 28 kg
MG FF/M Germany 20mm x 80RB ( 92 g ) 520 rpm 690 m/s 28 kg
MG 151/20 Germany 20mm x 82 ( 115 g ) 740 rpm 710 m/s 42 kg
MG 151/20 Germany 20mm x 82 ( 92 g ) 740 rpm 800 m/s 42 kg
ShVAK Russia 20mm x 99R ( 96 g ) 800 rpm 800 m/s 42 kg
B-20 Russia 20mm x 99R ( 96 g ) 800 rpm 800 m/s 25 kg
Hispano Mk.II French, British, U.S.A. 20mm x 110 ( 130 g ) 600 rpm 880 m/s 50 kg
Hispano Mk.V French, British, U.S.A. 20mm x 110 ( 130 g ) 750 rpm 840 m/s 42 kg
Type 97 (Ho-3) Japan 20mm x 125 ( 164 g ) 400 rpm 820 m/s 43 kg
Type 1 (Ho-5) Japan 20mm x 94 850 rpm 750 m/s 33 kg
Type 99 mod 1 Japan 20mm x 72RB ( 142 g ) 490 rpm 555 m/s 23 kg
Type 99 mod 2 Japan 20mm x 101RB ( 142 g ) 490 / 750 rpm 750 m/s 36 kg

juzz · « **Reply #3 on:** May 09, 2000, 04:18:00 AM »

MG 151/20 Germany 20mmx82(115g) 740rpm 710m/s 42kg
MG 151/20 Germany 20mmx82(92g) 740rpm 800m/s 42kg

Synchronisation on the two wingroot guns slows down the ROF, usually by 15% I think Pyro once posted.

I think the different round weights are for different types of HE shells, the lighter one is the "Mine" type HE shell.

As you can see the Hispano Mk II fires heavier shells at higher speed than the Mg 151/20 -> more hitting power.

MANDOBLE · « **Reply #4 on:** May 09, 2000, 04:24:00 AM »

MG 151/20 Germany 20mm x 82 ( 115 g ) 740 rpm 710 m/s 42 kg
MG 151/20 Germany 20mm x 82 ( 92 g ) 740 rpm 800 m/s 42 kg

Probably none of those, 115g and 92g ammo are just examples, there are more than four different kinds of rounds for the Mg151/20 and they usually are mixed, for example AP/HE, AP/EI, etc. I'm probably mistaken, but I think only AP rounds are modeled in AH.

Vermillion · « **Reply #5 on:** May 09, 2000, 07:32:00 AM »

Quote

I'm probably mistaken, but I think only AP rounds are modeled in AH.

Not sure Mandoble, but I think back in open beta there was whole discussion with Pyro on cannon shells, explosives, and the damage model. And I thought it was said that cannon shell explosive effects are in the game.

Anyone else remember? Its been many many months ago now.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

CavemanJ · « **Reply #6 on:** May 09, 2000, 08:13:00 AM »

HE shells for the cannon are in the game. Dinnae about EI rounds for the MG151/20 though.

Pongo · « **Reply #7 on:** May 09, 2000, 09:49:00 AM »

Juzz...
Heavier round..more velocity = more kinetic energy effect..
Doenst effect explosive energy at all. Might acctualy hinder the explosion of the round within the airframe (which is the intention)
Higher explosive to casing content -> lighter round for size -> worse ballistics -> but bigger boom
But if the ballisics are still great within say 600 yards vs fighter size targets then what have you lost. Will the ballistic supperiortiy of the HS realy come into play in air combat?
Vs the MGFF...... Definatly...
VS the MG151......thats the dilema. No account I have seen from the war indicates it had a noticable advantage. In the game it certainly has a large advantage.

If Ballistics at extreme ranges or kinetic vs explosive energy are out of wack in favour of the high ballistics guns then...

We have to fix this or the MK103 will pooch the game. With radar ranging and zoom to 60X the 103 will be able to take down bombers at 2.5k....is that what we want? Then all these people will be saying "well look at pyros picture...See how big that 103 round is..."
Of course that flat shooting increadably hard hitting 103 should be able to HO my hawg at 2k...I feel real good about this....

And that is exactly the same thing as the hispano. Yes the Hispanos have GREAT numbers. And it was a GREAT gun. But at what point does diminishing returns kick in as far as balancing ultra ballistics vs realised leathality.....

ra · « **Reply #8 on:** May 09, 2000, 11:53:00 AM »

Good luck hitting anything at 2.5k, or at any range where you're using full zoom.

ra

Pongo · « **Reply #9 on:** May 09, 2000, 05:32:00 PM »

I would have aggreed until I saw panzers doing exactly that.

MANDOBLE · « **Reply #10 on:** May 11, 2000, 09:23:00 AM »

Just to clarify that enormous mess about HS and 151...
Lets suppose this data is correct:
MG 151/20 20mm 115 grams 710 m/s
MG 151/20 20mm 92 grams 800 m/s
HS Mk.II 20mm 130 grams 880 m/s

We have the diameter, mass and initial speed of each projectile. Now suppose the firing plane is cruising at 250 mph. And Now we only need an engineer to calculate and post here the vertical possition of the bullets at 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 yards relative to the flight path of the plane. For this example, we'll suppose the guns are perfectly aligned with the horizontal flight path of the fighter (no convergence at all and no lateral deviation).
If someone is so kind to do those calculations, please, post also the math formulae.

Vermillion · « **Reply #11 on:** May 11, 2000, 10:12:00 AM »

Mandoble, its easy to calculate if you negelect wind resistance, but if you wish to correctly calculate it you will also need to know each rounds ballistic coefficent. Which will determine how much the round slows down, and therefore how much time & vertical drop at each of those measurements.

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Vermillion
**MOL**, Men of Leisure
"Real Men fly Radials, Nancy Boys fly Spitfires"

MANDOBLE · « **Reply #12 on:** May 11, 2000, 10:34:00 AM »

I know Vermillion, do we have those coefficients?

Vermillion · « **Reply #13 on:** May 11, 2000, 12:36:00 PM »

No, sorry I don't and I don't remember seeing them posted by anyone recently. Somebody might have them around though.

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Vermillion
**MOL**, Men of Leisure
"Real Men fly Radials, Nancy Boys fly Spitfires"