190 A/F engine dammage Test

[Wilbus]

Another good idea Nexus, will do it if it's necissary or Pyro needs some more evidens or help to narrow down the problem with the engine.

The 50 cal, both US, Brittish and German, were indeed very good guns, the US 6 gunned and 8 gunned fighters such as P51's and P47's could rip wings of planes with a 1 or 2 second burts into it. However, I seriously doubt, that a plane flying straigth forward in 200Mph, and gets 2 hits in the wing, will go down cause it loses the wing, nomather what 50 cal it is (unless it hits a VERY Vital part).

This thread though, was mostly about the engine wich, I and alot of others, need to find out wether it is a bug or not and if HTC can find the problem (if any) and fix it.

     

[Toad]

Again, not arguing the damage model. By nature, that's a pretty subjective thing for the programmers to decide upon.

However, I see two major differences in the .50 BMG and the 13mm MG 131 rounds; projectile weights. 48.5g vs 34.6 and 870 vs 730 fps.

I think you'd get a larger difference in downrange energy & trajectory, especially since the .50 MG has an exceptional BC.
That's why it's still popular in heavy sniper rifles.

I wish we had the BC for the 131; it would be interesting.


Name  Ammunition (Bullet Weight)  ROF Fire Muzzle Vel

Browning .50 M2 12.7 x 99 (48.5 g) 750 rpm  870 m/s  

MG 131  13 x 64B (34.6 g) 900 rpm  730 m/s

[MANDOBLE]

IMO, this thread has nothing to do with projectile characteristic. Anyway, IMO, a single slow 13mm round loaded with HE is way more destructive than a fast 50'. Faster means for me cleaner hole, slower and HE means really serious damage.

[Hooligan]

Mandobile:

An AP-type round has the ability to penetrate into the "vitals" of the target aircraft and kill something really valuable (like the Pilot).  Whether of not an HE projectile is more or less destructive depends a lot on the nature of the target and where the round hits.  The information I have seen indicates that for this caliber, AP/I rounds were probably the best ammunition against fighters.

Hooligan

[Hooligan]

Toad:

Using trajectory data from military documents I have calculated G1-Ballistic Coefficients for a variety of rounds.

G1-BCs for .50 BMG are in the range of .65 (AP/I) to .72 (Ball)

G1-BCs for Mg131 are in the range of .20 (HE) to .36 (AP-tracer)

Hooligan

[MANDOBLE]

Hooligan, agree with you only partially. HE projectiles will be much more destructive against wing or tail surfaces, while AP could be more effective against "hard" points (engine or LIGHT armoured cockpits). IMO, "breaking" a wing with AP will require significant more hits than with HE, while less ammo to kill a engine.

[DmdNexus]

Friggin wrong thread

[ 06-22-2001: Message edited by: DmdNexus ]

[Toad]

Hooligan, thanks! I had never seen BC data for the German rounds.

Folks, if you've studied ballistics, that big a difference in BC makes a MAJOR difference in downrange trajectory and energy.

Mandoble, energy has to be a key part of the damage model. It's in there somewhere. With a this difference in downrange energy don't you think it would be interesting to see if you get the exact same results with the .50 BMG and the MG 131 round? Might be a clue Pyro could use.

Mostly, though, I was commenting on the idea that all .50 cal are equal in damage. This is not the case.

[Wilbus]

Never said they were equal in dammage, quite similair though, and they are. Doesn't mather wich one is best though, 2 of them won't rip a Heavily armored 190 F8 or A8 wing off.

Not exactly the rigth thread no, this one was about the enigne, can do another one with the rest of the plane  

[Toad]

Busy weekend, but I'll try to run a few ballistic comparisons on them now that I have a BC for both. Should be able to output a comparative trajectory and energy for different ranges. There's already some proven tables for the .50BMG so I'll be able to compare with those results and see if it all seems in line.

[Hajo]

MANDOBLE and I were engaged in a 1 vs 1 a few days ago, I managed to hit his engine, but I don't know how, I saw the hit sprites from my guns hit his craft from the canopy and walk down to the tail.  Was a good fight, I was in d9, but I don't know how I managed to get his engine from the position I was firing from???  Splain Dat?

MANDOBLE I was using cannon and mg at same time.  sorry for the late post!

[ 06-24-2001: Message edited by: Hajo ]

[GRUNHERZ]

You cant really compare the .50cal and MG131 in AH. Whatever the various advantages of the .50 or the MG131 might be they are overwhelmed by the fact any of the US fighters carry at least twice as many .50cals than does any LW carry MG131.

[Toad]

I haven't found the right online ballistic program yet. I wanted one that did trajectory and energy in 100 yard out to 1000 yards.

I know it's out there, I'll keep looking.

In the meantime, this one gives an interesting and insightful comparison:
 http://internet.cybermesa.com/~jbm/ballistics/maxdist/maxdist.html

Using the ballistic coefficients that Hooligan supplied and taking the WORST BC for the .50BMG (.65 AP/I) and the BEST BC for the 13mm MG131 (.36 AP/I) I used it to figure maximum range at an altitude of 15,000 feet and the energy at max range.

.50 BMG

Input Data
Muzzle Velocity: 2845.0 ft/sec
Bullet Weight: 712.0 grains
Ballistic Coefficient: 0.650  
Drag Function: G1  
Temperature: 5.5 °F
Barometric Pressure: 16.89 in Hg
Relative Humidity: 0.0 %
Altitude: 15000 feet
Air Density: 63 % of Sea Level


--------------------------------------------------------------------------------

Calculated Data
Maximum Distance
Firing Elevation: 36.0 degrees
Terminal Range: 8468.0 yards
Maximum Height: 7421.7 feet
Terminal Angle: 60.3 degrees
Terminal Velocity: 661.9 ft/sec
Terminal Energy: 692.7 ft-lbs
Time of Flight: 40.8 secs


Absolute Maximum Height
Maximum Height: 17322.0 feet
Time of Flight: 27.4 secs

13mm MG131

Max Distance Output

--------------------------------------------------------------------------------

Input Data
Muzzle Velocity: 2460.0 ft/sec
Bullet Weight: 534.0 grains
Ballistic Coefficient: 0.360  
Drag Function: G1  
Temperature: 5.5 °F
Barometric Pressure: 16.89 in Hg
Relative Humidity: 0.0 %
Altitude: 15000 feet
Air Density: 63 % of Sea Level


--------------------------------------------------------------------------------

Calculated Data
Maximum Distance
Firing Elevation: 35.0 degrees
Terminal Range: 5520.0 yards
Maximum Height: 4729.5 feet
Terminal Angle: 61.5 degrees
Terminal Velocity: 508.0 ft/sec
Terminal Energy: 306.0 ft-lbs
Time of Flight: 32.9 secs


Absolute Maximum Height
Maximum Height: 11400.0 feet
Time of Flight: 21.5 secs
****************************

Check the comparison of Maximum Range and Terminal Energy.

.50 BMG Terminal Range: 8468.0 yards
13MM MG 131 Terminal Range: 5520.0 yards

Note that the firing elevation is essentially the same for both.


.50 BMG Terminal Energy: 692.7 ft-lbs
13MM MG 131 Terminal Energy: 306.0 ft-lbs

Perhaps you can relate better to this tidbit of data.

44 Remington Magnum/246 gr @ 50 yd = 623 ft-lbs

9mm Luger/115 gr @ 50 Yd = 306 ft-lbs.

So the .50 BMG hits with double the energy at its terminal range which is also greater by ~60% at 15k.

This is also on a Worst .50/ Best 13mm Ballistic Coefficient comparison as well.

So, indeed, all .50's are not created equal. In this case they are not even close.

[MANDOBLE]

Yesterday and today same effects.
Yesterday a P51B scored a single ping somewhere my 190A8, engine stopped, no smoke, no other damage. Today same history. And one of my squad mates was hit also, engine stopped, and no more damage.

Sincerelly, THIS IS INCREDIBLE!

As it is the effect of single ping, vertical stab gone against acks, over'n over. That or engine stopped.

Ok, 190s were "historically" paper/crystal planes, but 190s HAVE MORE PARTS TO LOOSE! What about horizontal stabs, ailerons, pilot, guns, flaps... Engine or rudder have, for some unexplanable reason, 90% chances of being damaged over any other part of these dammed planes.

[mrfish]

wasn't the bmw801 engine an aircooled radial? did it also have a radiator?