Jump to content


Photo

AP vs HE ammo comparizon/calculations


92 replies to this topic

#41 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 10:34 AM

anyone able to find NEOPUP 20mm HEI ammo data, other than weight/muzzle velocity? HE amount and the type of it?

 

anyway, here is that rounds effects on steel skin targets, barrel, steel skin door and car door. anyone can themself estimate the diameter of those holes. fragment holes indicate that it has quite thick steel shell. its true that the ammo is modern. but those things work still in same basics. steel shell and explosives in it. grade of steel can be less brittle, which gives ability to put more powerful(faster burninng) HE in it. If the steel/iron would be brittle, it would just turn to dust. also the less brittle but hard the steel is, thinner shell walls can be used, and more HE can be put in it(this with heavy artillery pieces at least)

 

anyway, i took those pictures from that weapons effects, compare the shell size to hole it has made on 1mm steel:

(its 30cm wide..  =15 times to its own caliber)

20mm_1mm_steel-hei.jpg

 

heres same round, shot at 3mm steel, not that HE is not anymore effective against it, just fuze is able to penetrate it(12-15mm hole from it)

i bet it could not penetrate much more with its fuze, but AP ammo of cannons/machineguns would easily.  this is where AP ammo starts to shine compared to HE, penetration capablity

20mm_HEI_3mmsteel-hei1.jpg

 

 

same round against barrer, dunno how thick its steel skin is

 

 

20mm_vs_barrel.jpg

 

 

car door, front:

20mm_vs_car_door_1_front.jpg

 

same door, rear:

20mm_vs_car_door_1_rear.jpg

 

steel door front and back, same ammo again:

smaller hole is 12cm x 20cm in size, IF that is standard US door, which is 91cm wide.

bigger hole is 22cm x 40cm in size

20mm_vs_steel_door.jpg

 

 

same door from behind

20mm_vs_door_rear.jpg

 

Every hit from that NEOPUP 20mm seems to use impact Fuse, as on every picture above, impact side of target skin is bend inside the target, away from the shooter. That exactly tells us that round explodes outside the target, not inside. you can see rear part of the targets have the edges as well bent away from shooter.

some pictures show good fragmentation damage as well which would not be possible in that size if round would have thin shell.

so i believe that it is designed to have fragmentation effect against soft targets, as its marketing team is comparing it to 40mm Ace tube, which has smaller muzzle velocity, and much worse hitting propability due high arc rounds have compared to 20mm, this due the recoil.

same issue when comparing MK108 vs 20mm cannon but even way smaller muzzle velocities, cos weapon is hand held, not installed in 2,6-3,5ton aircraft which in turn can and could handle the recoil.

 

 

here is 20mm Vulcan hits on SUV during training exercise. source said it was training ammo, as people inside that SUV would have gotten more wounded during those hits. happened in 2008.

most propably that ammo had CMPSN A4 HE on it. were not able to find its comparizon against TNT effectivenes.

 

062508af_suv_800.jpg

 

 

here is some modern 20mm Ammo data, perhaps made for marketing the ammo for "customers" :) it has some nice pics and info on it. especially delay fuse difference is nice.

 

it also explains that  velocity indeed HAS effect on HE ammo fragments, expecially on thick shell HE, not minengeschoss ammo(cos this has so small/nonexistant fragments).

fragments seems to fly in around 30-40 degree cone to direction of round, at around 500m/1500 feet per second initially(plus some , plus fuse going forwards at velocity it had at impact plus some over 500m/1500feet velocity due explosion. thats the reason why fuze from neopup 20mm was able to penetrate the 3mm steel.

 

this also tells why there is in most cases, no fragment damage in those pictures above in aircraft hits, cos round have hit it at good angle. there would be fragment holes if it comes at poor angle, so that helps to identify better the angle of impact with HE frag ammo.

 

velocity of round before it hits and detonates defines the angle which fragments of shell walls take. more slow it hits , more at sides they spread in "ring shape", faster the round more cone shaped the "ring of fragments" is towards to direction of round.

 

http://www.dtic.mil/...ay/dillard2.pdf

 

heres some results of artillery ammo, it has really good pictures for how artillery round fragments spread, though it seems that velocity of round in pictures is always the same.

also, artillery shells have MUCH more HE in them sending fragments at way higher speeds around

http://nigelef.tripo.../wt_of_fire.htm


Edited by Stafroty, 25 June 2014 - 01:57 PM.

  • 2

#42 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 12:51 PM

found pretty good video from spit gettin hit from 30mm mine shell.

 

http://www.youtube.c...h?v=ZoLLDi-M3fk

 

took screen shot of it. it seems to be spit V or IX(?) as it has 20mm cannon bulge on its wing.

checked its wing span, and from that started to divide that to get measure for comparing damaged area. i compared photo with spit rivet lines etc to get as close to truth measures. and from those i calculated the area.

anyone can check those if finds need.

if wing span is wrong for current plane, someone can tell what it is :P i believe there is no big difference. proportions still hold if that spit would have non elliptical wintips unless they changed whole wing structure and gun placement as well.

the hit in pic was fired directly from astern at 100m distance.

spit_wing_damage_pic.jpg

 

rear part of the wing measures varied from .08m to 0.9m so i took average .8m from it.

 

(oops, i compared upper wing surface damage area whole wing area, i dunno if they are different, so % calculations might be wrong.)

spit_9wing_damagearea.jpg


Edited by Stafroty, 25 June 2014 - 12:54 PM.

  • 1

#43 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 01:09 PM

not totally sure if this is the exactly same wing than in the picture. You still can see landing gear in the top part of the damaged area.

just painted over stucture which spars etc are bent/missing, to tell that it does also something else than shred skin, it does structural damage as well.

 

 

spitfire-pr-iv-xi-wing.jpg


  • 1

#44 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 01:19 PM

to compare damage to cannons, here is vid from P38 (nose mounted .50cals) shooting planes. notice the first 109 being hit. it puffs white steam as it is already hit in inner part of left wing. its radiator is leaking. still it gets peppered some more, but nothing too magical happens structucally. many planes takes really many hits on those vids, but no major structural damage is made on them, perhaps controls got broken, or pilot dead, but no losing wing/tail from hits. on one instance fuel tank gets hit and lits up. Dunno how many .50 cals they had in nose. Anyway, they still did the work. Just not the same way cannon HE ammo does.

 

 

http://www.youtube.c...detailpage#t=58

 

heres picture to show placement of 109 coolant radiators.

f_coolant.plan.jpg


  • 1

#45 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 01:42 PM

just tried to count visible hits from german (20mm cannon?) 109 against spits etc.

first 12 targets.

 

 

1st target hits: none.

2. 4-6 hits, hard to tell cos of smoke

3. around 10 hits? hydraylic oil burning? or just Incendiary stuff stuck on undercarriage structure?

4. 2 hits, 1 on both wings.

5. 2-3 hits. first at radiator, then maybe on left wing, after that right wing

6.  5 hits. first at radiator, second at left fuselage with little puff. right wing 3 timeswith mine/He ammo perhaps

7.didnt see any.

8. 3 hits at least.

9. too hard to say anything.

10.  3-4 total, 2-3 hits top of frontal part fuselage, 1 at wing

11. perhaps AP hit on radiator, seems leaking white stuff or smoking. no puff of smoke/flash from hit.--

12. 1 hit.

 

those pilots had hard time getting guns on correct lead it seems, also you can see when pilot starts to shoot, as camera starts to shake. cant say how much that camera zoomed if at all.
 

 

http://www.liveleak....=cca_1340813172


  • 1

#46 BuccaneerBill

BuccaneerBill

    Squadron leader

  • Members
  • PipPipPipPip
  • 1,394
  • 41 Thanks

Posted 25 June 2014 - 02:16 PM

That 20mm gun does struggle against that 3mm plate with HEI but I think that's because of its low muzzle velocity.  The Hispano irc could penetrate 6mm of armour with HEI. Nice work btw.


  • 1

#47 _13codyrex

_13codyrex

    212th Attack Battalion Commander

  • Members
  • PipPipPipPipPipPip
  • 6,616
  • 304 Thanks

Posted 25 June 2014 - 02:28 PM

found pretty good video from spit gettin hit from 30mm mine shell.



took screen shot of it. it seems to be spit V or IX(?) as it has 20mm cannon bulge on its wing.
checked its wing span, and from that started to divide that to get measure for comparing damaged area. i compared photo with spit rivet lines etc to get as close to truth measures. and from those i calculated the area.
anyone can check those if finds need.
if wing span is wrong for current plane, someone can tell what it is :P i believe there is no big difference. proportions still hold if that spit would have non elliptical wintips unless they changed whole wing structure and gun placement as well.
the hit in pic was fired directly from astern at 100m distance.
spit_wing_damage_pic.jpg

rear part of the wing measures varied from .08m to 0.9m so i took average .8m from it.

(oops, i compared upper wing surface damage area whole wing area, i dunno if they are different, so % calculations might be wrong.)
spit_9wing_damagearea.jpg

how many times have I seen that video.

If you really want to prove it to people, find some other video to help your claim.

Just like I can say to the picture of very damaged flying B-17s I can say the same for that video.

A rate occurrence and a isolated case.

Not to mention a perfect test with no outside variables.

Find something else.


Edited by _13codyrex, 29 June 2014 - 07:19 AM.

  • 2

usq0uzn.jpgdU9LIUm.jpg4bsAu0G.jpg

Signatures by Carrier_ (link)   War Thunder Index Page


#48 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 05:59 PM

huh? in this case it seems just something you dont want to believe/see, so you refuse it completelly. You can yourself look the sructural damage in that video, you can see inside stucture picture of that wing and compare that in picture i captured from it. Just use little time for it.

 

In this case, it seems it is no matter of evidence but the lack of ability to accept it, not think of it. Perhaps its because you have already make up your mind. Its common in everyday life with different people in different issues.

 

You can do those calculations urself what i did. to check it. You also can check others as well, to see if they stand to truth.

Now, you dont do it, just look it with mind which already before even lookin it, thinks that its false, wrong  and not true.

so there is nothing which can change your mind, but to see it urself, with real thing at shooting range, at real target plane, with different caliber ammo with different kinds of ammo at different angles of shooting, and examining urself all the results/penetrations etc, and looking inside there too. No other thing in life would convince you. This you can agree if you think it abit of time.

 

P.S. Just take ww2 era pineapple hand grenade. it has less explosive power than MK108 round had. it had around 56 grams of explosives, while 108 round had 72-85 grams, and they both are from same era.

 

anyway, here is washing machine vs hand grenade for you. its made from steel, it has 2 layers of it plus other parts as well. Effect is quite big dont you say. And, the space inside it is bigger than in airplane wing, which have only 1 layer of aluminium. Also, in this video, he doesnt shut the inner door of the machine, just the outer one.

Also, IF, which it with high possibility is, this grenade: http://en.wikipedia....iki/M67_grenade it has 180grams of HE in it. average 100 grams more than 30mm. 120% more. so bit over double the amount.

 

first value is g/ml, second value is detonation speed m/sec,third is relative effectiveness factor, or R.E. factor, relates an explosive's demolition power to that of TNT

Compound B information: 

Composition B (63% RDX + 36% TNT + 1% wax) 1.72 7840

1.33

PETN information

Penthrite (PETN) 1.71 8400 1.66

 

This gives the amount of TNT per type of grenade:

30mm mine ammo 141,16g of TNT

M67 hand grenade 239,46g of TNT

its 98,3 g more in M67 hand grenade.

its 58,9 % bigger amount of explosive power.

 

 

so, now lets see, some 6-10g of He can cause at minumum 10cm hole on aircraft. thats minumun, it can be nearly 30cm or more, as all holes arent round, depending the angle it hits. well, lets think it makes that average 15cm hole.

So, you increase the amount of explosives some 10 times, 1000%. What could it do? still 15cm hole?

 

also, calculations for PETN isnt including aluminium powder in it, which increases its exploding effect, as it turns the gas explosing creates even more hot, which creates even more pressure. As you must know, hot air balloons use hot air(which also is gas) to get airborne and stay there too. its because air in it is expanded from its atoms, taking bigger area in space, while colder air around it takes smaller area(is heavier than hot) that makes it kinda float like wood on water. Same princible.

 

at least when comparing that washing machine taking 1800% more than 20mm HE what is needed to make 15cm hole...

how you calculate the increase in effect with increased amount of explosives? im intrested to know, would you explain that to me?

 

 

http://www.youtube.c...h?v=YQEVGhVN9oc


Edited by Stafroty, 25 June 2014 - 06:05 PM.

  • 3

#49 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 25 June 2014 - 06:11 PM

so, should we now look at AP ammo and the way it will work.

 

its harder job, as, it doesnt open the skin/structure to reveal as easily its damage capability. so, we need cut through pictures of plane. And on that, make some magic bullet theories.

 

Here is car door, which took really many hits from calibers up to .50cal. If its hinge would be ok, you could still put it on car.

Though it would not look nice, at all.

 

car_door_.50_7_62.jpg

 

there is around 200 holes on that door, someone care to count? and if someone would, make also count from different cals, little ones and big ones. you can see it from the size of hole, except from those points which took really many shots at exact same area, eating bigger hole in it. someone earlier asked to shot effect on REAL target by those AP hits. Here is steel "sheet", a car door. You can bet, that every round also penetrated the rear side sheet, easily. I bet Smaller rounds penetrating that door lost some 10-40% of their total kinetic energy. (im not talking about muzzle velocity energy, but the energy they had left when they met that door.

.50 cals most propably didnt lose that much. Thats an assumption. I could claim here,that the rounds could only penetrate only 1 door, and after that they would be useless, just because i dont see behind it, and that there is no witness plate behind it and all that. Would i do it? no.

 

Here is just for comparison, also a car door, hit with  20mm on its side. 2 shots, one hit the window and other.. (yes its modern ammo, impact detonating HE-I)

how i know its impact detonatin? because steel around the hole is bend away from shooter towars that witness plate behind it( which has dents from fuze parts of those ammunition. thickness of that rear plate is unknown as is hardness.)

 

care to think/count how many AP hits it would take for them to eat similar size of hole?

i did :) about 700 shots from 7,62mm and 260 12,7 hits.

20mmHEcardoor.jpg

 

here is same door, before it gets hit with 20mm HEI. coming from left, notice the door handle on both pics.

as well, upper spar where that door is hanging, is welded behind those 2 other ones standing tall, on both pictures as well.

 

20mmcardoorinflight.jpg

 

still hard to believe in impact fuse and direction of fire?

20mmcardoorimpact.jpg

 

shot hits and explodes right away. some incendiary is going to other side of door, but HE detonates on this side of the door, thus bending the edges away from explosion cause of pressure (= its like really really strong wind blowing for a really brief time.)

 

 

 

I am intrested if anyone got pictures of penetrations from WW2 era AP rounds, no matter if its light mg ammo, or .50cal ammo or 20mm cannon ammo.

Its known, that those weapons can penetrate steel plate from 8mm thick to closer 30mm thick with AP round, dont know about 20mm cannon exact values, as there were different cannons with every nation, and each had different charasterics in ammo velocity, ammo weight, rate of fire..

But with weight and speed one can calculate somewhat accuratelly the penetration capability of each cannons round on single plate. 

 

It is known, that every single penetration through something affects the projectile. It affects its velocity, trajectory, stability=making it unstable and perhaps weight as well. All depending what it hits and at what angle, how heavy projectile is and how fast, its shape etc. And how many times it penetrates something, every time it does so, above mentioned effects increases.

Its a fact, that if you keep caliber and velocity of ammo, but double its weight, its penetration is doubled.

and when you keep same caliber, ammo weight but double its velocity, the penetration is 4 times as much.(and accuracy at long ranges increases because of flatter trajectory, if ammo isnt light comparing to its size. Heavier material can sustain its speed longer time, as will tracer element in its back(reduces drag effect somewhat). also shape has big factor in this. 

(best shape for keeping ammunition speed i know (without assistance)is that in the picture below, developed in late 1800´s by swiss professor Hebler.

the shape and air passage reduces air and material resistance huge amounts. Iron made 5mm bullet of such shape was able to penetrate stack of wood(pine) some 204 cm.

 

(i believe hunting rifles around .308cal are able to penetrate wood some 40-80cm these days.)

 

it was using kind of sabot behind it to keep gunpowder created pressure behind it, thus forcing it at speeds 1220m/sec

similar 8mm bullet was able to fly 4402 m, and it took 9,16 seconds to get there. It still had velocity at that range some 337m/sec and penetration against wood 27,8 cm. Calculated max range was 8101 m. Pretty good for "AP" ammo of 8mm, at 1890.. thats before over 20 years before WW 1.

 

(Perhaps adding flechette style thin wings on its tail section would help it keep its course? :P)

 

Heblerammo.jpg

 

 

 

back to track.

 

So, AP ammo penetration capability against harder surfaces is also affected by angle which projectile hits the thing, like armor plate.

 

angle___penetration.jpg

 

 

If you shoot at armor plate at 30 degree angle(above picture show 45degree, so 15 degree more angle) it means that projectile has to penetrate twice as much material to make it through. At surface side of plate, plate resist the penetration because material gives in more on the surface side than inside the plate, cos surface side there is room for material to move at, but inside the plate, there is no room. It goes opposite way, when projectile starts to penetrate and comes closer the inner side of the plate, then there is again room for material to move away from path of projectile. so, as above picture shows, 45 deg hit, it it penetrates, it would first turn the projectile more upwards, but when its close to other side, its nose would turn downwards(level), cos material gives in on that side.

 

to clarify that what i mean,  again short vid which shows how upper part of simulated aluminium plate over the projectile move over(right wording?) and that guides the projectile back upwards. its just because over the projectile is less resistance for material to move.

 

http://www.youtube.c...h?v=MI_hu7stdQM

 

there were different kinds of ammuniton used to prevent that ricochet from happening, at least some degree.

 

here is schematic picture of 109. everyone can see the different parts inside that plane. Most of the WW2 planes have quite the same equipment inside of them, just in different numbers, sizes and places, with some different values as well. Now example is 109.

imagine that you are shooting it directly from behind with 6x .50 cals, at convergence range(which is the meeting point of projectiles, spot where guns are aligned to meet each others fire. the Deadly zone. The burst hits right in the left wing (the wing closer to you, under the fuselage) in the middle of it. it would not take too long to make it Fold/snap under stress while turning and if its not turning(not stressed that much), it would demand little more hits on it then to make it happen. I bet everyone agrees that .50cal bullets would quite certainly go throu entire wing, from rear to front part.

Most of the rounds just need to penetrate 4 layers of aluminium. Im not sure if the main spar is made from steel, might be. Someone can bring that information to light. (too tired to dig it up now)

Some of the bullets might hit the cables running inside the wing, and most likely also cut them, depending how it hits that cable.

Some wing ribs might also be holed up with long cuts, because fire is coming paraller to them.

also rear part of the wing skin would  have longer cuts on it, because rounds are hitting it at high angle. from front of the wing, angle isnt that bad, and the holes would not be that big, IF bullets would come out at clean stable trajectory, and wihtout bullets broken in parts. But they have torn in parts, or are flying sideways because skin penetration and penetrations after that, forcing them to lose some of their stability. Some of them come out clean, some comes out sideways, and some in pieces. Most of them lost nose part of their copper jacket, as those had incendiary stuff in their nose, making copper jacket deform/rippin off.(i assume some of them had that in their nose due the flashes in vids, which tells that they are sensitive to impact pressure, causing that stuff to "detonate", which is seen as flash.  Some part of that incendiary goes inside the wing, but there is nothing to burn except tire which is rubber. it would exhaust quite Soon™™, as it isnt too willing to burn on itself, after incendiary burns itself up. Tire would be tho "flat", not in flight but when landing, as it needs mass over it to deform that rubber shape it is cast into, when it loses pressurized air from inside of it.

Plane could do it without it. Undecarriage though would be damaged even more if it would land without air in tire.

Rim(?) would also be punctured by bullets and landing would do more damage to it.

 

Quite many planes have wing as thick as 109 wing, on fighters. clear exception from that is Hurricane, which wing is 30cm(1 feet) thick.

Any fighter plane would last almost as long as 109 wing under .50cal barrage at convergence range. just depending on its thicknes, IF rounds are able to penetrate whole wing.

Exceptions are those, which have more wing spars than one- Two would perhaps mean, that even if both are damaged, it would still be able to withstand more stress/hits, because the fact that there is 2 of them holding the wing in its position, thus sharing the forces. 3 spars is even better, as forces are perhaps divided evenly. that perhaps might not be true, as it might be possible, that depending on spar position, it matters alot.

as, if you remove 2 spars from the forward part of the wing, it might not withstand, but would turn like elevator wing and then rip off.

 

 

AP rounds compared to HE rounds are able to tunnel in the plane, deep. able to make hole in several internal strenghtening parts. But same applies locally with cannon HE shells, as well at longer distances with thei fragments, though fragments arent possessing the kinetic energy what 7.62/.50cal/20mm AP rounds have at close/medium ranges. at close range they got enought to put holes in aluminium structures/skin. Mine ammo shells have really poor fragment effect because thin shell and size of fragments it created, except fuse which will get speed Boost from detonation in additition to its velocity when it hit the target. Same applies to fragments but not as much. (10-20% difference)

 

AP bullet, depending on caliber, is able to travel from tail to fuel tank without much problem, depending on how many inside structures/equipment it hits on its path. HE ammo cannot do that.

HE stop at surface or just under it and damages it and surrounding stuctrures, plus make holes at frontal sector of its fllight path with fragments, depending how fast it was when it hit. it it is standing still fragments would fly from side of grenade to sides of it etc, base part would fly away from it at its rear direction, fuze would go at its nose direction. frontal part of the sides, which is angled, would take forward directions.

 

AP round penetrating tail can hit oxygen cylinders behind pilot, making them explode. I dont know how much pressure there is, if they are full, the force is up to that and also that how much it is spend. if the pressure is low, it doesnt do anything. But if is pure oxygen and not air, it will certainly boost fire if there is such and cylinder has leaked its oxygen inside the fuselage. Though, holes in the skin would also mean, that there is ventilation effect inside, effectivenes of it is up to speed plane travels, as well altitude it has, as well amount of hole area in its hull, as well where the hole or holes are. if there is 1 at frontal part and second at rear part, it works better than a single hole, i assume.

This also is bad thing, if fuel tank is hit, it could make fire burn inside the fuselage at high heat because of continuous airflow, making it kinda blowtorch, depeds how much air gets inside front of fuel tank/leak position. I think that way it would be more effective. But if air is spent inside the fuselage, fire would burn ouside of it, where is air/oxygen for making it possible. Temperature(high) weakens the structure.

 

 

killing pilot thru the rear armor of 109 is quite hard if not impossible from directly behind, because of few reasons. first is that upper part of it is angled, which makes it quite impossible to be penetrated, as picture above shows. higher the impact angle, harder it is to penetrate. Under that angled armor is plate, which has no angle. that should be easy to penetrate. But no.

All of the rounds first have to penetrate rear skin at high angle, then perhaps some structures, most of them will hit radios, which "armor" value i dont know or cannot guess. After those there is fuel tank. I dont know that from which material it is made, but it as well, works as protection for pilot, much more so, if it is full of fuel, (which is rare thing to be)

it might be quite hard if impossible to kill pilot directly from behind. i dont know, but some gun vids gives impression that it is so. targeted 109s keep maneuvering after fuselage is hit from behind  or nearly behind at place where pilot would be.  from side, it is totally possible. In this case actually, Cannon HE shell might be more effective in wounding or perhaps killing the pilot, if its shot from behind or nearly behind, hitting side of the cocpit, which then gives fragments free path to pilot. Pilot would die if frag would hit him at spine, brains or hearth, instantly. well, spine would just paralyze him.  Anyway, there is in my earlier post that Spitfire pilot, who received 3 hits from MG FF cannon behind his cockpit, and he was wounded in legs because of that :o which i wonder how it was possible. Or was he hit with light machineguns as well, which caused it? dunno, also i dont know what kind of pilot armor that spit had in times of BoB.

 

Control surfaces are harder to destroy with AP ammo, as it demands huge amount of bullets, or hit at hinge of it, which attach it to main frame/wing.

Or it demands that control wires are hit and cut, or parts are bent/deformed which are linked to that wire, making it loose, and if that happens, stick movements doesnt anymore transfer via wires to control surfaces so much, it would make hard maneuvers that way impossible. But this also applies with cannons as well.

 

against engine AP ammo also have bigger change to effect, again because of their penetration capability. they can enter fuselage at cockpit area, and still go at engine compartment thru firewall/instrument panel. HE ammo would stop at cockpit area from most parts, and fuse isnt having the same power as higher cal AP has.

in that kind of areas AP rounds shines against HE ammo. Much better. they arent in that case, comparable, as they arent in structural damage as well.

 

HE ammo also cannot travel trough wing from behind and hit ammo box at frontal part of it, but AP ammo can. It can ignite gunpowder from them, or even detonate its ammo. Minengeshoss ammo is the easiest to detonate, because of their thin walls compared to normal HE ammo. PETN is also sensitive to detonate from such hit. Also if the fuse of it is hit, its quaranteed detonation or explosives. That creates really big explosion what is seen when FW190s are hit on wing. Explosion is white because gun powder also goes off, though, its likely, that PETN or Incendiary ammo creates white puffs as well, as is seen in german guncams. some hits from german make black puffs from explosions, but some are white. i know TNT makes  black cloud. i think ANFO also makes black, as this video indicates. (first thing coming up from ground is black explosion gas with smoke in it, after that follows more heavy dust of earth, then bigger pieces, all in order of mass. lightest things accelerate fastest.

 

Tho this has nothing to do again with issue :P

http://www.youtube.c...h?v=saU3ftuG7CQ

 

 

Like i have said, the effectivenes of them is based differently in reality. the way they work are completelly different. They are invented to work differently. Their purpose is to work differently. 

 Its like using Fragment shells against tanks. (every early tank was vulnerable to 75mm-76mm cal HE shell actually, and i believe Russian T-111(T-46-5) was first tank to be able to survive 75mm HE shells. front armor was 60mm thick. this at least according one book i got..

 

anyway, my conclusion is:

 it takes alot more hits from AP rounds to produce as much structural or skin area damage to aircraft than it takes cannon HE ammo.

it takes more HE rounds to burrow inside aircraf trough all to layers/equipment to reach penetration depth which AP rounds posses.

AP is able to reach parts from angle which HE ammo cant. But, also there is that If you hit engine cowling with AP but it doesnt hit engine or its pipes/electric wires etc, it just goes off, wihtout doing much, and wiht HE ammo, detonating on skin next to engine, would do damage to those parts.

Both of the ammo types have advantages and disadvantages.

But if i would have to choose, i would take cannon because of its destructive power.

and This is what every country have chosen. Every one of them is using High explosive rounds in their cannons. I dont even know, if there is AP ammo at all for them, except for tank buster cannon, like GAU-8, with its depleted uranium rounds. (this gun was designed for anti tank role from the start, not for Air to Air battle.)

 

Attack Choppa Apache has Dual Purpose rounds, which have fragmentation body, and really small hollow charge in nose of it. Round is filled with 28 g of explosives(behind copper cone of course)  it cannot penetrate MBT:s with that small HEAT, but light armored vehicles it can. I dont penetration value of that HEAT on it, but it cannot be much, but i believe its more than what that cannon could do with AP rounds. otherwise it would shoot AP-HE belt? Though, DP ammo makes both of that with same ammo :P And, muzzle velocity on that cannon isnt too big, or accuracy, according vids. (you can calculate how far they shoot approximately, if you know muzzle velocity. Though it drops fast because it is partly empty(hollow charge cone) plus it has light material in it (HE stuff).

 

 

 

Here is picture of that 109 for everyone to imagine bullet penetration paths through different parts and angles, as well to imagine what would HE rounds do at same area of hit compared to AP hit, from same direction.

 

109example.jpg

 

 

 

heres P-47 pic also for you to think about how ammo would work in different places on it.

P-47Cutaway.jpg


Edited by Stafroty, 25 June 2014 - 10:09 PM.

  • 3

#50 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 26 June 2014 - 01:56 AM

Heres some more about AP ammo.

pictures(there is also video of these, captured pics from it)

 

so, here is first entry holes of M60 7,62mm machinegun, rear door of car:

(holes are somewhat the size of the caliber of ammo, just bit bigger, but same applies to every AP round, so not taken in account.)

 

7_62vsCarDoor.jpg

 

Next picture shows .50 cal API ammo on front door of that same car. I believe that ammo used it more modern than what was used in WW2 era. (yea, ive seen that same claim said for comparing more modern explosives vs WW2 era ;)  ) Holes are quite near the caliber of the round, again perhaps bit more bigger, because material is soft enought for copper jacket to penetrate as well, attached to round or not. against armor plate copper jacket is left behind on other side of plate if round would penetrate.

 

50calvsCarDoor.jpg

 

 

Next we have car hood, which has high angle hit on it, from .50cal API ammo, it really cuts it.

that high hit angle for sure makes area of skin damage much bigger, than its own caliber.

 

50calvsCarHoodCut.jpg

 

and the last picture, it is not showing anyhere that there is penetration from 7,62mm bullets, at least i am not able to find similar shape group as is on the first picture. was guns shooting car at 4-5 o clock direction. least it looked like .50cal was.

 

:)

But there is .50cal API exit holes, i assume that the width of that car is nearly 2 meters(6,6 feet)

So bullets hits first the outer skin of the car doors, then there is inner side of that door, same steel.  then, almost 2 meters of empty space, then next door like the first one, but in opposite order or skins(which doesnt mean anything, the order i mean)

i assume that nose of those API rounds contain the incendiary material, under the copper jacket. It "detonates" in contact with first of second layer of first door. (not like explosives, but still, breaking the jacket and spreading the incendiary and jacket parts. Spread of jacket parts isnt big, only about degree or two apart from projectile trajectory.

Its seen clearly on the picture, as how big the exit holes are, as they had room to spread out. They still contain enought kinetic energy to come through from other side of door, causing quite big holes in there. there is fragmentation effect, as few of those .50holes have smaller holes next to them. I again assume, that longer the distance is before the second surface, more they spread, as well lose their kinetic energy, but on about 2m distance they still have it alot. Shorter distance between doors would have caused perhaps smaller hole, and longer bigger. 

 

I draw one spreading cone to illustrate how the fragments of jacket etc PERHAPS spread after initial hit on first door.

diameter  of those exit holes is about 7-10cm, or even more. Thats perhaps after war API rounds.

 

It would be nice to find wartime photos of exit holes on german/italy/japan planes from .50 cals.

there is no need for light cal ones, i believe everyone agrees this one?

 

What is most suprising to me, is that API ammo failed to ignite the car interior as there is seats which are quite easy to ignite and burn. Though, in engine area it looks like engine is leaking burning oil.

isnt that all above mentioned sounding really nice? yea it really is, but..

 

 

that all would be true, IF ammo would be just API ammo

 

50calvsCarDoorexit.jpg

 

 

but some idea i got that that is not just API ammo of .50cals, but quite modern HEIAP rounds.

here is citation about them:

 

"The triggering of the explosive charge is dependent upon the resistance of the target. If the target offers little resistance then the lack of frictional heating will prevent the incendiary from igniting and the high explosive from detonating."

 

650px-Raufoss_NM140_MP_%28en%29.svg.png

http://en.wikipedia....cing_Ammunition

 

And indeed, when lookin more carefully that video, it clearly shows that doors gets more hits than just few from that ammo, Multiple of those and there is not enought large exit holes for them, to make my earlier conclusions to hold.

 

it also is clear on vid, that it really needs to hit something much harder most of the time, to make that round explode. bottom of the car detonates nearly every shot, as well does tire area and engine area.

some few of those shots are detonated by  enough resistance offered by door on the other side thus making big exit hole. Still size of those which detonated amazes me :) But, there is MULTIPLE holes at the door which shows that the exit hole is just around the caliber of the .50cal round if round failed to explode on it.

 

 

 

there is quite much funny talk on wiki about that ammo, like

 

"HEIAP munitions use high explosives to "blast a path" for the penetrator"

above citation doesnt hold common sense.  Why?

 

blast path through what? :)

 HE element is front of the Tungsten penetrator, it slows it down when the HE detonates, which decreases its penetration capabilities.

IF that HE would be behind it, and would be triggered by fuse reacting to resistance(round slowing down),  hitting "nail" on back of the fuse, it would accelerate the penetrator and improve the penetration, yes still causing HE effect. I dont believe that the picture about the ammo is telling the truth.

 

Lead Steel in its base? huh?

 

there is no point inserting the incendiary element in the tip of the round. it is wiped off on the surface of the target if it would be in that place and would not affect inside the target(and fuel/other burning stuff)

 

also that source claims that incendiary stuff on that round can burn up to 15 minutes? whole article is a joke. in video they dont burn even a second, only once there is longer burn but thats the tracer element flying.

 

2 different types of incendiary on it. Why not Nuke as well?

 

"The MK 211 is claimed to penetrate up to two inches (51 mm)"

thats with full cal ammo without sabot and with explosives front of it to "blast path for it" :)

 

why dont they install explosives in tip  of APFSDS rounds to blast path for penetrator?

 

about other gun ammo:

 

"Larger guns such as the British 30 mm RARDEN cannon fire APSE (Armour Piercing Special Effects) shells which are an armor-piercing round with added HE effect."

 

 wasnt panzer grenade in WW2 time just like that. AP round with small HE load in its rear part? :) both russians and germans used that kind of ammo, it helped observing where the round landed, because of that HE effect, so fire could be adjusted if needed. It also Affected after penetration effect due some fragmentation or rear part of the penetrator.

Now its "special effect" shell.

 

 

I really would like to have WW2 era pictures from .50cal etc AP style  ammo.


  • 2

#51 Jaakariliike

Jaakariliike

    Group captain

  • Members
  • PipPipPipPip
  • 1,705
  • 199 Thanks

Posted 26 June 2014 - 03:37 AM

Stafroty, you might find the following files interesting:

 

The first one is a US report on the effectiveness of various calibers against P-47s and B-25s. You can get it here: http://oai.dtic.mil/...ifier=ADA800394

It basically says that 20mm minengeschoss (and 30mm) are most likely to get their rear-attack, near-instant kills on bombers through structural damage, and to get their rear-attack slow kills from either structural or fuel damage. .50 cals, on the other hand were most likely to get their kills through pilot or fuel damage. 

 

The second document is here (sorry, best link I could find): http://www.mediafire...rom 50 cals.pdf

It is a translation of German testing data. It talks about the effects of .50 cal hits (I believe - I can no longer find the full document, but it is specifically discussing bullet holes rathers rather than cannon shell holes). Regarding hits against the main spar of a Bf 109, it says:

u1GSLPd.png

 

Essentially, the 109 (and I believe many other fighters) have stressed skin construction. This means that the skin of the wing is in tension and is ready and able to take much of the load, should the spar flange be damaged. Furthermore, the spar itself can have large holes in it and suffer no ill effects. I once posted a picture of a 109 prototype wing where the cannon was housed inside the wing. To do this, the main spar had a huge hole cut in it (really, there was barely any height of material left at the widest point of the hole), yet the design still flew fine and did not rip its wings off.

Also, you asked about what the spar was made of - it's duralumin (so are the ribs and the skin). I don't think many WW2 aircraft had steel structures.

 

Really, it seems that AP rounds do most of their damage through causing fuel leaks or fires and killing or wounding the pilot. Structural damage kills are very common with explosives, but much less common for AP rounds, in general. Fighters were designed to be able to take some hits and still fly back. I'm still always shocked when pro-.50 people insist that US .50s must have been able to kill pilots through armor, must have blown off wings after several hits and would have left huge ragged holes in the skin. The reports from both the US and the Germans indicate otherwise for the latter two points. As for the first point, common sense would indicate that rather than increasing the armor of the cockpits if it had no effect, they'd just remove it (save weight; why add more weight if it won't stop the weakest round you regularly face?).


Edited by Jaakariliike, 26 June 2014 - 03:38 AM.

  • 2

#52 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 27 June 2014 - 01:46 AM

i agree jaakariliike. And i believe many others agree as well.

 

What is true is that plane cannot fly if it only has its internal stuctrures (skeleton) left. there is no surface which is making the light, but just shapes which resist the airflow.

 

This is true especially true with HE hits from cannon. Of course, every size hole matters, protortionally to their size.

 

it is easy for everyone to test, just put your hand out of car window while its moving on motorway. first keep fingers closed and its a fist.  then open the hand, so its totally flat against the wind. there is much more resistance on it then. fold few fingers and resistance gets smaller. compare the effects with amount of fingers. This very same applies to aircraft and their skin damage.


  • 0

#53 SunsetShimmers

SunsetShimmers

    Stat Padder, Kill Stealer and Coward Camper

  • Members
  • PipPipPipPipPipPip
  • 6,343
  • 630 Thanks

Posted 27 June 2014 - 04:28 AM

 

p-51_mine.jpg

 

I just love how you scaled up the size of the hits to the bomber, when the P-51D image is smaller scale.

 

Totally a sign of a good poster to make epic mistakes like that.

 

 

 

P51s were quite fragile.

 

P-51s were only fragile because of the inline engine.

 

Their structure was as over-engineered as nearly every other American built plane, so they were actually quite durable.


Edited by Cuteling, 27 June 2014 - 04:29 AM.

  • 1

#54 Taranok

Taranok

    Wall of Text Construction Specialist

  • Members
  • PipPipPipPipPip
  • 2,229
  • 447 Thanks

Posted 27 June 2014 - 04:31 AM


P-51s were only fragile because of the inline engine.

 

Their structure was as over-engineered as nearly every other American built plane, so they were actually quite durable.

 

Eh, the radiator was hilariously vulnerable on the P-51 (probably its most vulnerable part followed by the engine), and the P-51 actually wasn't as structurally over-engineered as "nearly every other American built plane."

 

The P-51 was the first one to get rid of a lot of the over-engineering, but it was still a structurally sound plane compared to most of its competition.  It was still a very heavy, durable, long range plane.  A requirement when you're trying to provide bomber escorts over Berlin when launched from England, while being able to retrieve the plane without losing the pilot for any reason.

 

It was still significantly stronger than a Spitfire, though, and no one can touch the Zero or many other Japanese planes for raw lack of durability, but that's the price Japan paid for ultra-lightweight planes made out of an aluminum alloy that was known for being exceptionally fragile from impact stress (I.E. it tended to fracture when impacted instead of dented or deformed).


  • 1

#55 SunsetShimmers

SunsetShimmers

    Stat Padder, Kill Stealer and Coward Camper

  • Members
  • PipPipPipPipPipPip
  • 6,343
  • 630 Thanks

Posted 27 June 2014 - 04:41 AM

Eh, the radiator was hilariously vulnerable on the P-51 (probably its most vulnerable part followed by the engine), and the P-51 actually wasn't as structurally over-engineered as "nearly every other American built plane."

 

Reputedly, a single 7.92mm to the radiator was frequently enough to down the plane.

 

 

 

The P-51 was the first one to get rid of a lot of the over-engineering, but it was still a structurally sound plane compared to most of its competition.  It was still a very heavy, durable, long range plane.  A requirement when you're trying to provide bomber escorts over Berlin when launched from England, while being able to retrieve the plane without losing the pilot for any reason.

 

IIRC, some of the structural lightening done in the P-51F/H was removal of the need for lateral 2G tolerance, and lowering of the landing gear deceleration requirements.

 

The XP-51F ended up some 1600 lbs lighter than the P-51D when empty, but the P-51H apparently put much of that weight back on, as it was only 1100 lbs lighter than the P-51D.


  • 0

#56 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 27 June 2014 - 07:40 PM

I just love how you scaled up the size of the hits to the bomber, when the P-51D image is smaller scale.

thx for reply.

Im not following you here totally. If i understand you correctly, you mean that i just compared wings over each others to make that size of hole on P-51 wing?

Well you can see the calculations there made for P51 wing. Sure it is problematic because the picture on it is at angle, not directly from above. So, to make it more accurate against P51, as i use it as an example plane to compare hole area HE ammo makes(not total area damage which included bending stuctures, detaching partially the skin by loosing rivets or fragmentation effect. Just hole it tears on skin, and from that its easy to see, what size of sphere the explosion is with its total destruction diameter. This would not stand exactly with diameter, but is greatly affected if its surface or internal detonation. In surface, half of the sphere is outside the skin, and in internal, much more inside the plane, and that also would mean boost to pressure damage around it.

So, i made picture for you, where i got whole wing span of P51, its 11,28 metres. I divided by 2 to get half of that. Half is 5,56 metres, i again divided that with 2 and its 2,82 metres, again dividing by 2 to get 1,41 metres, dividing again by 2 and 0,705m, again by 2 and its 0.3525m, and again by 2 and its 0,1762m.  One meter is 100cm(centimeters) 1 cm is 10mm.

So the smallest measure there archieved by dividing is 176mm= 17,6cm. and then, making from those smallest measures, its quite easy to fit around 20cm circle in there.

30mm Mine ammo is having weak damage if it only makes 60cm diameter hole. If russians/german guns are able to do  10cm or bigger hole with around 6-10g of HE, and 18g HE is able to do bouble of that with about 2,2 times more explosives. 30mmMG(72-85g) rounds has 4-4,7 times more HE than 20mmMG with 18g, or 7,2-14,1 times more than normal HE ammo on russian/german ammo(6-10g of HE) that would mean that it should then make hole between 72cm-141cm hole (diameter) If its effectiveness scales up. So 60cm diameter hole is at the lowest possible results there can be for that imo. (sure structures inside the plane arent round, but more square in shape inside the wing, so damage would spread more in that shape inside, or on outside skin of the targer, and in structures around the hit zone. that area is just converted to circle.

(Here is anyway pic of P51 with correct size 20cm and 60cm spheres on it, as now the angle isnt affecting the size of hole. (though the hole diameters took from german bomber wing were angled, making them having smaller diameter perhaps than if picture would be taken directly from above.. )

 

 

20-60p51.jpg

 

 

 

p-51_mine.jpg

 

Comparing the areas on the pictures show that you are right with scale change. I believe it doesnt work to calculate width with picture that has target in angle.

 

but, did just calculation with vertical hits:

 

 

To saw P51 totally in two from wing tip to wing tip would take 57 HE ammo which makes 20cm hole, if they hit just perfectly next each other in line.

0.2m x 57 = 11,4m

 

To archieve same result with .50cal ammo, it would take over 868 rounds from it, if they connect next to each other in direct line.

 0,013m x 868 = 11,284m

 

nevermind bout that.

 

Back to AP business vs HE (gotta say, that current calculations i got here at my computer makes AP rounds look good, excellent. Just making or at least trying to make them and HE ammo also, to fit in realistic conditions.  Not just vertical hits etc.

 

consider this as a teaser :  1x .50 cal bullet hole is 1,27 cm²  when striking vertically 

                                       at 45 degree angle, its about 1,5 times bigger

                    near paraller, 10 degree hit, from single .50cal AP makes 64,7cm2 area damage.

                         its JUST about 51 times bigger area than with vertical hit ;) and more better, cannon HE ammo is not able to Do it too well cos they explode and dont travel in the material surface..  to be continued.


Edited by Stafroty, 27 June 2014 - 08:04 PM.

  • 1

#57 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 28 June 2014 - 10:23 PM

Heres picture i draw which shows  how AP ammo area damage is affected with hit angle, this only simulates single sheet of target with 2 different thicknes.

 

(Totally paraller hits would not be able to travel thru thin target for whole penetration value against given material, unless the tip of the bullet travels right in middle of target sheet(and stays in that), otherwise round would start slowly to ricochet. How long cut it could  make depends of speed, weight, shape as well of material of jacket  the round has(if any).

 

 

 

10mmangle_of_attack.jpg


Edited by Stafroty, 28 June 2014 - 10:51 PM.

  • 1

#58 Stafroty

Stafroty

    Warrant officer

  • Members
  • PipPip
  • 253
  • 20 Thanks
=FinFL= Finnish Fighting Lemmings

Posted 01 July 2014 - 02:03 AM

calculations still going, got some other pic, and gotta say  AP lovers went silent when values of cannon ammo went off "a little"  , bias cos such silence? :)  anyway heres nice picture of spitfire, with all measures and calculations there. will do others as accurate too and that calculation thing too to end with pictures and all that.

 

spit_2_blueprintvsphoto.jpg


  • 1

#59 SunsetShimmers

SunsetShimmers

    Stat Padder, Kill Stealer and Coward Camper

  • Members
  • PipPipPipPipPipPip
  • 6,343
  • 630 Thanks

Posted 01 July 2014 - 03:18 AM

 

0A6e0J2l.png

 

I went and measured those holes; the 30mm hit is 167mm x 226mm in size, and the 20mm hit is 118mm x 64mm in size.

 

 

 

 

Heres picture i draw which shows  how AP ammo area damage is affected with hit angle, this only simulates single sheet of target with 2 different thicknes.

 

(Totally paraller hits would not be able to travel thru thin target for whole penetration value against given material, unless the tip of the bullet travels right in middle of target sheet(and stays in that), otherwise round would start slowly to ricochet. How long cut it could  make depends of speed, weight, shape as well of material of jacket  the round has(if any).

 

High explosive shells are significantly affected by impact inclination too; too high an angle, and they either fail to fuse correctly or ricochet off.

 

 

 

 

calculations still going, got some other pic, and gotta say  AP lovers went silent when values of cannon ammo went off "a little"  , bias cos such silence? :)

 

argument-pyramid.jpg

 

If your response is in the lower portion of that pyramid, don't post it.


  • 0

#60 Amur_Tiger

Amur_Tiger

    Flight lieutenant

  • Members
  • PipPipPipPip
  • 1,046
  • 41 Thanks
[PETCO] PETCO

Posted 01 July 2014 - 11:37 AM

Wellington-bomber-fire-damage.jpg

 

Look at all that 'damage' Wellie must have been hit by a million calibre shell or something, I mean look at that 'hole' it goes around the plane!

 

Yet.... somehow... it flew home, funny that.

 

Perhaps damage to the skin of a plane doesn't have a significant impact upon the underlying structure and instead causes a lot more superficial but scary looking damage along the surface, outside of the wings and control surfaces damaging the skin of the plane won't have any guaranteed impact on their ability to continue flying beyond increasing drag.

 

Your damage isn't the hole you make in the skin, your damage is your ability to compromise the structure or critical components and in that respect AP shells certainly aren't behind by 26k times. While some shells did fragment not all had enough casing around the explosives to produce significant fragments, mineshells in particular were known for this as they explicitly thinned the walls of the shell to pack in more explosives.

 

Consider this analysis.


  • 2



Reply to this topic



  


0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users