Spitfire and 109 Weapon Data

[xHaMmeRx]

Greetings all,

I've gotten the 20mm and .50cal/13mm weapons for the Spit and 109 info up on my site.  Direct link to the weapon comparison page is

netAces Weapon Comparison Page

Plane specific stuff is at the bottom.

HaMmeR
www.netAces.org

[ 12-20-2001: Message edited by: xHaMmeRx ]

[ra]

Cool stuff Hammer, thanks for all the hard work.

ra

[Karnak]

Interesting.

I notice that on your 20/30mm Cannon page you have a test for both the Hispano MkII and the M2.  Those are the same cannon, just the British and American designations for it.

You don't have a Hispano MkV test however.

[xHaMmeRx]

Karnak, haven't gotten to MkV yet (it only on perk planes) as well as no 30mm, rifle cal MG's, and several others... it's a work in progress.

Interesting about the 20mm on the 38.  I hadn't bothered looking it up, but now I've found my sources that bother to identify the 20mm identify it as a Hispano.  Since the .50cal designation is M2 I was thinking the 20mm was same design as .50.  Oh well, learn something every day!

I notice you live fairly close to me.  Any aviation museums around?  Fairly new to the area.

HaMmer
netAces.org

[Tony Williams]

Some interesting diagrams.  A few comments:

The ShVAK and Beresin B-20 were ballistically identical; they used the same ammo.

Will you be adding the 20mm Type 99-1 and MG-FF?  In the case of the latter life gets complicated because the MG-FFM had different ballistics from the MG-FF, and the MG-FFM ballistics also varied between the M-Geschoss and the other rounds.  This latter point also applied to the MG 151.  If the ammo types were mixed in the belts (which they were) you would end up with two different clusters at long range.

The 20mm Ho-5 also had different ballistics for the HEI (79g) and APT (112-120g) loadings.

For the A6M you have listed a "12.7mm Type 2".  This calibre was not used by the Navy planes. There was a 13mm Type 2 which was basically the same as the MG 131, but I don't think that was used in the Zero - it was a flexible gun.  Late model Zeros did use the 13mm Type 3, which was a .50 Browning rechambered for the 13.2x99 Hotchkiss round.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://website.lineone.net/~a_g_williams/index.htm
Military gun and ammunition discussion forum: http://www.delphi.com/autogun/messages

[HoHun]

Hi Hammer,

highly interesting comparison!

There's more one could do with it:

By finding out the size of the circle that includes 68% of the strikes in a pattern, you'd have an estimate of the weapon's standard deviation so you'd arrive at a numerical estimate of the pattern size.

Since they value is mainly determined by the mounting, you could then go on and compare wing mounted and centreline mounted cannon of the same type to determine whether Aces High models any difference there.

(I'd guess the standard deviation increases linearly with range, so one range for each weapon would do.)

Another information you could extract from the pictures is the trajectory (by measuring the vertical distance of the centre of the pattern from the bullseye for each range).

With the trajectory graph, it would be possible to calculate the drop of the projectile velocity over range to get a complete picture of each weapon's ballistic capabilities :-)

Regards,

Henning (HoHun)

[xHaMmeRx]

Greetings Tony,

In response to your questions/comments...

 

Originally posted by Tony Williams:
The ShVAK and Beresin B-20 were ballistically identical; they used the same ammo.

I had read this before... hit patterns seem to confirm it!  

 

Will you be adding the 20mm Type 99-1 and MG-FF?  In the case of the latter life gets complicated because the MG-FFM had different ballistics from the MG-FF, and the MG-FFM ballistics also varied between the M-Geschoss and the other rounds.  This latter point also applied to the MG 151.  If the ammo types were mixed in the belts (which they were) you would end up with two different clusters at long range.

I plan on doing each gun as it is found in Aces High.  So far, I have found no indication of mixed ammo.  As for the specifics mentioned above, the MG-FF is found on the A5 if I recall.  The challenge will be isolating them from the other cannon.  I don't think the Type 99-1 is found in the game, but maybe you could help me out with the difference between a Type 99 Mk2 as found on the AH A6M5 and the Type 99 Model 2 as found on the N1K2-J.  Are they the same?

 

The 20mm Ho-5 also had different ballistics for the HEI (79g) and APT (112-120g) loadings.

Again, so far at least, there is no indication of different ammo types.

 

For the A6M you have listed a "12.7mm Type 2".

Yep..my bad.  That was a place-holder thrown in there without references just knowing there was an ~.50 on the zero.  Should have put the correct designation in before posting.  Will fix it when I actually do that gun!

Thanks for the input!

HaMmeR
www.netAces.org

[xHaMmeRx]

Greetings HoHun!

 

Originally posted by HoHun:
There's more one could do with it:

By finding out the size of the circle that includes 68% of the strikes in a pattern, you'd have an estimate of the weapon's standard deviation so you'd arrive at a numerical estimate of the pattern size.

LOL HoHun, you're an ORSA, aren't you?  

 

Another information you could extract from the pictures is the trajectory (by measuring the vertical distance of the centre of the pattern from the bullseye for each range).

With the trajectory graph, it would be possible to calculate the drop of the projectile velocity over range to get a complete picture of each weapon's ballistic capabilities :-)

I'd actually thought about this but decided it was more information than I wanted/was willing to extract.  I'd need to collect more shot-pictures at smaller intervals... not worth it for what I am trying to discover/show.

HaMmeR
www.netAces.org

[HoHun]

Hi Hammer,

>LOL HoHun, you're an ORSA, aren't you?

Does that mean "Operational Research System Analyst"? I don't think so :-)

But the standard deviation would be easy to do, one pattern per weapon, with a limited number of rounds (like 100, for convenience).

>I'd actually thought about this but decided it was more information than I wanted/was willing to extract. I'd need to collect more shot-pictures at smaller intervals...

Actually, 200 yard intervals should do nicely. What's the width of the rings? I think I might have another look at the patterns you posted.

Regards,

Henning (HoHun)

[Tony Williams]

Originally posted by xHaMmeRx:
Greetings Tony,

In response to your questions/comments...
 
www.netAces.org

The designations for the Japanese 20mm naval aircraft cannon get a bit complex.  Basically, there were two models, usually referred to in English as the Type 99-1 and Type 99-2.  These were very different, in that the Type 99-1 fired a 20x72mm cartridge and was much shorter than the Type 99-2 which fired a 20x101mm round.  Muzzle velocity of the Type 99-2 was therefore around 750 m/s compared with 600 m/s for the 99-1. Incidentally, the Type 99-1 was pretty well identical to the MG-FF in design and performance (there's a history and faminly tree of the Oerlikons on my website, but unfortunately my ISP has temporarily managed to lose the site....

Now the complicated bit; both the 99-1 and 99-2 were made in various versions, which in English are generally given Model or Mark numbers.  The major variations to note are that the Model or Mark 3 was generally available with a 100-round drum instead of 60-rounds, and the Model 4 was belt-fed.  There are also sub-models, with distinctions being made between fixed and flexible versions, but a complete list would probably fill a page.....

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://website.lineone.net/~a_g_williams/index.htm
Military gun and ammunition discussion forum: http://www.delphi.com/autogun/messages

[Tony Williams]

Originally posted by xHaMmeRx:
Greetings Tony,

In response to your questions/comments...

HaMmeR
www.netAces.org

Second response: the 20mm Type 99-2 was fitted to both the A6M5 and N1K2

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://website.lineone.net/~a_g_williams/index.htm
Military gun and ammunition discussion forum: http://www.delphi.com/autogun/messages