US ww2 issue 20mm HE VS: 55gal. empty oil drum

[brady]

CC Karnak,  I was going on purely memory and spaced the detail about the Artilery Tolerances.

..............

 From what I understand on the P-38's this replacing of the 20mm was in part do to issues with the 20mm, also the reports I recal came largely from Pacific theater referances, at least the ones I recall do.

............

 Ring, I thought that test was prety darn cool, espichaly the last shot with the 20mm.

[Crumpp]

Yes I have and it wasn't any more impressive.

This is a lot more impressive:

http://www.axishq.wwiionline.com/~ring/info/ammo/wing-test.wmv



Than this:

http://www.axishq.wwiionline.com/~ring/info/ammo/GlacierGirl20mm.wmv

Getting hit with 20mm was bad but you cannot argue with more explosive.  As they say in demolitions, the formula "P" for plenty works.



Crumpp

[Karnak]

Crump,

How can you say that the first film is more impressive?  The chunk blown out of the barrel was bigger than the entire structure in the first video and made of a much, much stronger materiel and structure.

The test of the German round was against something that was not large enough nor did it match any aircraft structure.  The test while neat looking was done too poorly to tell us anything other than the round was explosive.  The Hispano round would have blown that piece of aluminium and wood completely apart too.  Yay.  It doesn't tell us anything.


I have no doubt that the German round would put a bigger hole in an aircraft.  However these tests don't tell us that.  The explosive content does.

To do a real test would require an aircraft structure large enough to survive the blow.  Then the respective damage could be compared.  Say, a junked 707's wing or some such.

What I am getting at, and you are steadfastly ignoring, is the tendency of certain people to romatisize the German hardware to the point where they have drasticly unrealistic expectations of Allied hardware.  There is a group of WWII buffs out there that would have claimed the Hispano round would simply have made a little hole in one side of the barrel, exploded inside, and made a small collection of tiny holes from shrapnel.  That is clearly not what happened.

[GODO]

Originally posted by Karnak
I have no doubt that the German round would put a bigger hole in an aircraft.

A would not classify as "hole" what a mine shell can do in an aircraft.

[Karnak]

Originally posted by GODO
A would not classify as "hole" what a mine shell can do in an aircraft.

Everything is a "hole", unless you claim that a hit from a mine shell would take a B-17's wing clean off.

If that is the case, you're delusional.

[GODO]

Originally posted by Karnak
Everything is a "hole", unless you claim that a hit from a mine shell would take a B-17's wing clean off.
If that is the case, you're delusional.

Was thinking on a spit wing.

[Karnak]

MANDOBLE,

Talking about damage and relatively fragile aircraft is pointless.

Spitfire and Bf109 wings were prone to breaking off when strick by a 20mm round.  That doesn't really tell us anything.  You need to look at bigger things like Ju88, B-17 and Lancaster wings.

[Guppy35]

Originally posted by brady
Thier were some diferances between the US and British Built Hispanos, the US ones suffered from reliabality issues, largely do to how they were made, specificaly US tolerances differed (a bit slopy) and resulted in weapons that tended to jam, in fact they were so problematic that drastic meashures had to be taken to inshure their operation. In some instances I beleave P38's they were often removed, in F4U-IC's and the Helldive they had to superlube the ammo to make them work, and I beleave they still had issues after that had been done.

Can't complain too much about reliabilty since that was a 50+ year old gun, firing 50+year old ammo after being locked in ice all that time

Dan/Slack

[Crumpp]

Everything is a "hole", unless you claim that a hit from a mine shell would take a B-17's wing clean off.

You need to look at bigger things like Ju88, B-17 and Lancaster wings.

The Luftwaffe commissioned a study on A/C weapon effectiveness against the Heavy bombers.

It concluded that it took an average of 15 rounds off 20mm to guarantee the destruction of a Heavy Bomber.

The average fighter pilot could only land around 2 percent of his rounds on target.  This meant an FW-190 firing it's total ammo load could only land between 10-12 rounds.  Hence two fighters would be assigned to one bomber in order to ensure destruction.


Now it only took 2-3 rounds of Mk 108 30mm to have the same effect.

What I am getting at, and you are steadfastly ignoring, is the tendency of certain people to romanticize the German hardware to the point where they have drastically unrealistic expectations of Allied hardware.

Actually I think it is the other way around.  People tend to view the Kinetic energy delivery of the Hispano's as much more powerful than the chemical energy of the M-Geschoss rounds.

You even hear the argument of M-Geschoss "bouncing off".

Anybody ever fly FA 2.5?  The Hispano's were one-shot wonders and could hit out to 1800 meters while the MG151's were not much better than a. 50cal.

All based off of kinetic energy delivery calculations.

Facts are the Luftwaffe did a very good analysis of air-to-air weaponry and chose the correct philosophy.  This is back by Tony William's excellent research into fighter armament effectiveness.

Now a fighter can take less damage.  One or two rounds of any 20mm HE should give you a great chance of knocking it down.

Talking about damage and relatively fragile aircraft is pointless.

Absolutely correct.

Was thinking on a spit wing.

Would be destroyed, as would a 109 or a 190 wing that took a hit in the main wing spar from an allied 20mm.  The allied shell would give a slightly higher chance of flying away but not by much.

Crumpp

[GODO]

Originally posted by Karnak
MANDOBLE,
Talking about damage and relatively fragile aircraft is pointless.

Not exactly, these 20mm weapons and ammo were designed well before large bombers got into scene. The massive air war in the East front was mostly against light bombers and fighters. Most if not all the LW aircrafts and weapons since 42 to 44 were designed to fit into this front.

[Karnak]

You miss my point.  It has nothing to do with the potential damage if a Hispano hit and a MG151/20 hit do the same thing.  You need a target that survives to compare damage.

[GODO]

Karnak, Im pretty sure most fighters will survive several hispano or MGFF-151/20 HE hits, except german 20mm mines, that is the point. Difference between any 20mm HE and mines are really relevant. Any fighter will keep in flying condition also with several or even lots of 20mm AP hits, except if pilot or engine is damaged.

[Crumpp]

Difference between any 20mm HE and mines are really relevant.

Very good point.  The M-Geschoss packs over twice the amount of chemical energy.  I don't remember off hand exactly what it was but I think it is PETN but do remember that it has a very high E factor.  Higher than TnT or C4.  Combine the speed of the explosive with the raw amount and M-Geschoss would have ruined any pilots day.

Crumpp

[Karnak]

Originally posted by GODO
Karnak, Im pretty sure most fighters will survive several hispano or MGFF-151/20 HE hits, except german 20mm mines, that is the point. Difference between any 20mm HE and mines are really relevant. Any fighter will keep in flying condition also with several or even lots of 20mm AP hits, except if pilot or engine is damaged.

Which is exactly what I'm getting at.  You guys act like the Hispano was AP.  It was not.  It is not punching little 20mm holes in the aircraft.


I don't have access to the quote, but I recall one BoB ear pilot who stopped combat flying just after the cannons were introduced.  He later, I don't recall why, was flying a combat mission and fired a very short spurt at a Bf109, something like 6 rounds from each cannon, and the Bf109's wing was instantly blown off.  He said he was very surprised because he had forgotten how powerful the cannon were.

As it didn't sound like he was particularly close or took careful aim it is unlikely many, or even multiple, rounds hit.


This constant talking down of the Hispano's lethality is really weird.

I agree that the mine round will do a lot more damage against the skin of an aircraft and weaker formings.  Things like the fuselage of a Spitfire would be particularly vulnerable.

I don't know that the mine round is the garunteed one hit, one kill wonder round you make it out to be though.  It is one thing against a Spitfirem but another against a P-47 and yet another against a Wellington or B-17.

FWIW, I pretty much consider a Hispano or MG151/20 HE hit a pretty likely kill against a Spitfire as well.  That is why I don't think talking about hits to Spitfires is very productive.

[Crumpp]

Which is exactly what I'm getting at. You guys act like the Hispano was AP. It was not. It is not punching little 20mm holes in the aircraft.

I know that and was not implying it did.  

This constant talking down of the Hispano's lethality is really weird.

Not aware that anyone was taking down allied 20mm lethality.

I agree that the mine round will do a lot more damage against the skin of an aircraft and weaker formings. Things like the fuselage of a Spitfire would be particularly vulnerable.

It would have done lots of damage no matter where it hit.

I don't know that the mine round is the garunteed one hit, one kill wonder round you make it out to be though.

If it hit and went off, most likely it would be a kill with one round.

 

It is one thing against a Spitfirem but another against a P-47 and yet another against a Wellington or B-17.

Depending on the plane and it's structural strength, of course.

You have to remember that Cannon rounds were mixed just like MG belts.  Not every round in the hopper was a M-Geschoss, HE, or AP.  Usually they were mixed.

FWIW, I pretty much consider a Hispano or MG151/20 HE hit a pretty likely kill against a Spitfire as well. That is why I don't think talking about hits to Spitfires is very productive.

I think this springs from the fact that the MGFF in AH is a very very weak cannon when it should not be at all.  The MG151's seem kind of weak as well.  I lit a Spitfire up the other night in a Snapshot Scenario.  Used nothing but MG151, he simply smoked and flew off like nothing happenend.  Whether this is modeling, a bug, or a connection issue (got cable) I don't know.

I am certainly not attempting to attack the Hispano.  It was a lethal air to air weapon.  You've got some great info Karnack.  Thanks for sharing.

Crumpp