Author Topic: Analysis of Aircraft Guns  (Read 4020 times)

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« on: September 25, 2003, 01:41:28 PM »
I've been curious for some time about the object damaging qualities of the different guns in AH. While I have heard things mentioned from time to time on this subject I have never seen an actual study. How much damage does a 20mm round cause? How much for a .50 round? How many bullets equal a 1000lb bomb? This sort of thing. Today I conducted a test. What follows is the test setup. Results and analysis of the weapons onboard the F4U-1C, N1K2-J, and P47-D30. Results of the total effective payload (guns plus maximum ordnance) of the respective aircraft. Possible errors in the test caused by range, poor gunnery, more rounds being fired than necessary, etc.

The test was conducted Offline on the Baltic map. Damage multiplier was set to 1.0, the default. Fighter Hanger and Bomber Hanger objects were set to values of .500, 500lbs of damage resistance. Each of the 3 test aircraft was launched from A43 and flew to A42 to conduct the tests. All AAA at A42 was destroyed using the destroy command prior to the planes arrival. This was done to prevent the AAA from interfering. Each of the Fighter and Bomber Hanger objects on A42 were restored prior to the test sequence for the aircraft. The guns of all aircraft were fired in controlled bursts of roughly .15 seconds to .75 seconds (quick tap or sustained burst). All passes were made at approximately 600 yards maximum closing to near point blank range. A different number of samples were gathered for each aircraft depending on available ammo supply. Before firing on a hanger the current ammo level was noted. After each hanger was destroyed the current ammo level was again noted. Each hanger was fired on individually; at no time was there more than 1 damaged hanger on the field. Each hanger was destroyed well before the 15-minute damage timer could expire.

F4U-1C
Gun Type: 20mm M2
Ammo Load: 924 rounds

                Rnds Req   Avg Dam in lbs
Hanger 1 163            3.07
Hanger 2 125            4
Hanger 3 125            4
Hanger 4 132            3.79
Hanger 5 128            3.91

N1K2-J
Gun Type: 20mm Type 99 Model 2
Ammo Load: 900 rounds

                Rnds Req   Avg Dam in lbs
Hanger 1 133            3.76
Hanger 2 135            3.70
Hanger 3 141            3.55
Hanger 4 137            3.65
Hanger 5 143            3.50
Hanger 6 139            3.60

P47-D30
Gun Type: .50 M2
Ammo Load: 3400 rounds

                Rnds Req   Avg Dam in lbs
Hanger 1 474           1.05
Hanger 2 475           1.05
Hanger 3 435           1.15
Hanger 4 507           0.99
Hanger 5 439           1.14
Hanger 6 469           1.07
Hanger 7 429           1.17

From the above tables the following conclusions and comments can be made regarding effective damage in pounds of each of the aircraft mounted guns.

1) I was surprised by how few rounds were required on the first sample with the F4U-1C. Since this was also the very first sample in the entire test sequence and since the results are so at odds with the other samples in the F4U-1C sequence it can be discounted.

2) Hanger kills 2 and 3 in the F4U-1C both required the same exact number of rounds, 125. This can be considered a near perfect result and validates the overall testing method. Please note that in these two tests the actual range to the target as each round was fired varied and hence the following comment is validated.

3) In previous posts to the BB at large it has been stated that cannon rounds have a fixed or near fixed damage level. This was stated to be an effect related to cannon rounds inflicting their damage based on the explosive quality of the shell rather than kinetic energy. Conversely, it has been stated that machine gun rounds inflict damage based solely on kinetic energy and therefore inflicts a variable amount of damage based on the range to the target. My apologies for not being able to refer to a specific post(s).

4) In several test sequences more rounds were fired than was necessary to destroy a hanger. The root cause of this was the firing of a short burst at a hanger that was already very close to the 500lb damage limit. This, along with the fact that a single round could not be fired individually causes the variation in the results shown in the tables.

5) Slight mistakes in gunnery did occur during the test. In some runs on the hangers a very small number of rounds actually missed the target. I was as meticulous as possible in my gunnery yet people can and do make mistakes. Of the 4629 rounds fired during this test I can safely state that not more than 2% or 90 rounds actually missed. I can further state that I believe that the level of error is much smaller probably on the order of 0.75% or perhaps 30 rounds. (only saw misses on 3 passes, 1 for each aircraft)

6) Based on the tables, observation, and comments the following values have been generated for each of the aircraft mounted guns on the aircraft.

20mm M2 damage per round is 4 lbs.
.50 M2 damage per round is 1 lb @ approximately 500 yards.
20mm Type 99 Model 2 damage per round is 3.75 lbs.

Conclusion: Effective Gun and Maximum Ordnance Payload

F4U-1C
Gun Payload: 3696 lbs
Ord Payload: 2624 lbs*
Total Effective Payload: 6320 lbs

N1K2-J
Gun Payload: 3375 lbs
Ord Payload: 1100 lbs
Total Effective Payload: 4475 lbs

P47-D30
Gun Payload: 3400 lbs @ 500 yards
Ord Payload: 4060 lbs*
Total Effective Payload: 7460 lbs

* rockets considered to be 156 lbs each based on previous posts to this board.

I invite any and all constructive criticism of this test, its' methods, and conclusions and hope to continue testing all other weaponry available in AH.

Thank you,
« Last Edit: September 26, 2003, 10:29:58 AM by scJazz »

Offline flyingaround

  • Nickel Member
  • ***
  • Posts: 422
hmmm....
« Reply #1 on: September 25, 2003, 02:06:08 PM »
interesting study.  Anyone else have similar data?  

Seems it could be done landed shooting friendly hanger in near identical condidions (distance, etc.)  I would love a full break down of the various guns,cannons.  

It seemed reasonably close to what I would imagine the damage to be.  

Thanks!

-Lute
III/JG26th 9ST
WMLute

III/JG26 9th ST WidowMakers

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Analysis of Aircraft Guns
« Reply #2 on: September 25, 2003, 03:58:10 PM »
As flyingaround mentioned, go offline, turn off "protect friendly objects" and simply taxi up to your own airfield buildings and strafe them down.  That way you can't miss and can get exact numbers for range and rounds.  You can always bump up the ammo multiplier to give planes more rounds so you can use things like the P-38 (with a single hispano) to get basically single round perfection on your firings.

-Soda

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #3 on: September 26, 2003, 06:30:07 AM »
I hadn't considered the idea of blowing up my own hangers. Thanks for the idea. In a way I'm actually glad I didn't since doing it the way I chose allowed statements 2 and 3. Cannon rounds do cause a fixed amount of damage and MG rounds do not. I will go hunting for the friendly object protection button though.

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Analysis of Aircraft Guns
« Reply #4 on: September 26, 2003, 09:11:50 AM »
You might want to test your points 2 and 3 again though.  You can always park your aircraft (not a tail-dragger) at some distance from a hanger and shoot and check.  The P-38 is perfect for this as it has both .50's and hispano.  Set the ammo multiplier higher and fire away at a bunch of different ranges and see.  You should get single round type accuracy with your numbers then.

-Soda

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #5 on: September 26, 2003, 10:25:49 AM »
Main problem is not knowing exactly what the range is when I open fire. Hangers don't have icons and hence no way of knowing exact distance. Unless you know a neat trick?

I can envision a map setup as a gun range but since I haven't a clue about the Terrain Editor I have no way of making this vision come true.

Map would basically have the HQ object set right at end of one runway. The land at end of runway would basically slope down to the HQ.  Quonset huts and the tall radio tower object found in Radar Factories would mark off range every 100 yards, using the radio tower at every 500 yard mark.

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Analysis of Aircraft Guns
« Reply #6 on: September 26, 2003, 10:40:59 AM »
A couple of thoughts:

1) if you are just looking to test the kinetic energy damage vs chemical, then you need not look for exact ranges.  You could simply drive up point blank using outside views to park right against the hanger (or JUST away from it so you don't take cannon shrapnel damage) and test.  That should give you values within only 1-2 rounds.  Then, just do the same thing but at some distance away and see of the rounds do less damage (ie, takes more rounds to kill it).

2) you can also use some features like the .target command.  .target X places a gunnery target at X distance from the aircraft, always to the north.  It gives exact ranges right to the yard.  You can probably use this to gauge your range to a structure by adjusting the X until you get the correct range.  .target 0 turns it off.

Just thoughts.

-Soda

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #7 on: September 26, 2003, 10:45:13 AM »
And very good ones... hadn't thought of using the target command to gauge distance to a hanger but that would certainly work.

See why I put this post up and asked for criticism!

Thank you!

Offline hitech

  • Administrator
  • Administrator
  • *****
  • Posts: 12425
      • http://www.hitechcreations.com
Analysis of Aircraft Guns
« Reply #8 on: September 26, 2003, 01:23:14 PM »
No need to test, with ground structures range has no effect.


HiTech

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #9 on: September 26, 2003, 02:11:10 PM »
Quote
No need to test, with ground structures range has no effect.
HiTech


And then the Lord spoketh and it was good and much confusion was caused to be avoided... thank you sir.

I must however humbly disagree. Obviously since you can not be wrong and I was so meticulous that I am not either, the source of the problem must be one of those creepy crawly things that sometimes gets into code.

Using Soda's suggestions I tested using an LVT and an A-20G. I cruised up to a hanger and commenced testing at 150, 250, 500, 650, and 1000 yards. I won't bore you with all the details that are not interesting. I'll just mention the ones that apparently disprove your statement.

Tests under 150 yards had very odd results. Specifically the LVTs .50 M2 machine gun took 407, 414, and 415 rounds to destroy a 500lb object. I have gotten very good at firing extremely short bursts with this machine gun at this point. Maximum error is a single round. I can fire 1 or 2 round bursts reliably. Every test conducted at 250, 500, 650, and 1000 yards took 400 rounds to destroy the target. No rounds missed the target during any of the tests. Similar results occured for the A-20Gs forward firing guns. Is there a problem with the damage function? Could the problem lie in the "bullet hit target" function? You might want to look into this.

Since you took the time to reply to this post perhaps you'll be kind enough to just give us a list of how much damage machine gun and cannon rounds actually do to ground targets. Please. Pretty please with sugar on top. Specially since I found a pretty bug for you to squish. For the love of god man don't make me do this full battery of tests! Please!
« Last Edit: September 27, 2003, 07:14:05 PM by scJazz »

Offline Batz

  • Gold Member
  • *****
  • Posts: 3470
      • http://bellsouthpwp.net/w/o/wotans/4JG53/
Analysis of Aircraft Guns
« Reply #10 on: September 26, 2003, 02:18:59 PM »
We tested this a while bach against ground targets and found range had no effect. Eack round translate to X lbs. If enough hit and add up to the structures hardness it gets destroyed.

We even made charts, but all I kept was lw stuff



All tests were done at main standard hardness.

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #11 on: September 26, 2003, 02:25:16 PM »
Hey Batz thanks for that table it will certainly help. Any chance that anyone else who helped in the creation has the non-LW section?

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #12 on: September 26, 2003, 05:40:21 PM »
A quick update...

I've tested the .30 M2 and .50 M2 vehicle mounted guns now. I've also re-tested the .50 M2 aircraft mounted gun. I suspected that there was a difference between the aircraft and vehicle versions of this weapon. There is of course. In addition HiTech's comments cleared up quite a few things and will make the whole testing process much faster. With any luck he'll make it even faster by just telling us the answers instead of making me go through and test the whole damn thing. (HiTech if your listening God will kill a puppy if you don't give us this table.)

Current tested values...

Weapon                     Damage per Round in lbs
.30 M2 GV                   .3125
.50 M2 GV                   1.25
.50 M2 AC                   1.17
Type 99 Model 2         3.75
20mm M2                    4

Additional Data from Batz (UNTESTED)
Weapon                     Damage per Round in lbs
20mm MG 151/20       3.5
30mm MK108              11.59

More on this subject as it becomes available.

Thank you,

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Analysis of Aircraft Guns
« Reply #13 on: September 26, 2003, 07:15:37 PM »
Quote
With any luck he'll make it even faster by just telling us the answers instead of making me go through and test the whole damn thing. (HiTech if your listening God will kill a puppy if you don't give us this table.)


What exactly are you looking for anyway?  I mean, is the exact number of lb's/bullet all that useful or the differences between them?  HT has said that range is not modeled against GVs for purposes of kinetic energy hits.  I mean, it's probably not even worth modeling to be honest.  The table that Batz provided is useful to see what kind of ammo you will expend destroying things but I'm not sure what you are getting after now?

Besides, ground structures can't whine that they got shot down with a lucky shot, overmodeled gun X, etc..

-Soda

Offline scJazz

  • Copper Member
  • **
  • Posts: 339
Analysis of Aircraft Guns
« Reply #14 on: September 26, 2003, 08:47:00 PM »
A deeper understanding of the environment is always good. Specifically the question is... what is the best JABO plane and why? Which plane brings the most to the table? Yes, P38s and P47s and 110s appear to be on top of this list but just how good is good? To put it another way just how many 110s does it take to turn the HQ into a smoldering ruin. How many buildings can a M3 destroy on its' own?