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General Forums => Aircraft and Vehicles => Topic started by: Pongo on January 19, 2010, 12:43:40 AM

Title: 20 mm in action
Post by: Pongo on January 19, 2010, 12:43:40 AM
(http://i225.photobucket.com/albums/dd135/humebates/phil_and_plane.jpg)
(http://i107.photobucket.com/albums/m299/Martosaurus/rassp36.jpg)
Tail wheel gone, radio gone, fairings from the horizontal stab gone.
Nice fusing, Hard to believe he landed it. Ben Afleck wouldn't have been able to.
Title: Re: 20 mm in action
Post by: Serenity on January 19, 2010, 09:59:09 AM
Hey, this was taken out by me! :D

Those shell holes certainly don't match what we have come to expect to be 20mm... would have thought there would be much bigger holes from the explosive.
Title: Re: 20 mm in action
Post by: Pongo on January 19, 2010, 10:03:05 AM
Its exactly what I would expect.
The round enters and explodes small hole for entry and lots of shrapnel out the other side.
It says they counted 544 bullet and shell holes, probably 400 of them were caused by those two rounds.
The first day of the war the US had all the evidence they would ever need to commit to 20mm.
Title: Re: 20 mm in action
Post by: jdbecks on January 19, 2010, 11:48:26 AM
The first day of the war the US had all the evidence they would ever need to commit to 20mm.

because of the lack of stopping power so to speak?
Title: Re: 20 mm in action
Post by: Westy on January 19, 2010, 02:14:31 PM
Great topic Pongo.  got me to wondering about him and the few P-36s that got
airborne that day and I found this:

http://findarticles.com/p/articles/mi_qa3897/is_200210/ai_n9121096/
Title: Re: 20 mm in action
Post by: Wmaker on January 19, 2010, 02:38:58 PM
Nice pics Pongo! Hadn't seen these before!
Title: Re: 20 mm in action
Post by: stran on January 19, 2010, 04:09:32 PM
those two holes in the first picture look pretty big.
Title: Re: 20 mm in action
Post by: Pongo on January 19, 2010, 04:14:39 PM
because of the lack of stopping power so to speak?


Look at that, he has a little bandage on his middle finger for you...

Even if 4 50 cal rounds hit in the same tight area, it would be 8 holes unless you got very very lucky.
The reason those pictures are historic is that that is devastating damage from 2 Oerlikon 20 mm rounds.
IE a hit from a 109e4 would do the same thing.  I presume the P36 had pilot armour like the early P40s. That is likely the only reason he is alive. The back of his pilot armour must be sprinkled with fragments just like the left side of his airframe is.
Title: Re: 20 mm in action
Post by: Pongo on January 19, 2010, 04:24:16 PM
From Westys link
"Phil Rasmussen recalled, "At almost the same instant, I was hit by two 20mm explosive cannon; one, in the radio compartment behind my head, shattered the canopy above me. The other, in the tail section, severed my rudder cable and blew off my tailwheel. In addition, I was stitched with 7.7mm bullets. Having hardly any control over the aircraft and scared as hell, I popped into a cloud, struggled to stabilize the plane and headed for Wheeler."
 very minor damage.
"
At that moment, the third Soryu Shotai arrived. P02c Jiro Tanaka-a wingman-attacked Thacker from the side. Thacker says, "A 20mm explosive shell had fractured my tailwheel hydraulic line. That, and other minor damage to the plane by small calibers ... I smelled hydraulic fluid in the cockpit, so I quickly ducked under some clouds and left the scene." P02c Tanaka put in a victory claim on the assumption he had shot Thacker down.
"

3 cannon round hits on 2 planes and hydraulic damage to both. And controls cut.
Title: Re: 20 mm in action
Post by: Yeager on January 19, 2010, 05:16:11 PM
explosive = shrapnel.  Depending on the mass of the exploding projectile and the kintetic power unleashed by the explosion.  These pictures I have seen before and am reminded of other accounts of HE rounds detonating upon contact with the aircraft skin causing considerably less damage to the airworthiness of the airframe than if they had delayed a few instants and exploded deeper within the structure.  And of course building airplanes like armored tanks helps out as well.
Title: Re: 20 mm in action
Post by: Karnak on January 19, 2010, 05:37:30 PM
Those rounds hit one of the best locations for the receiving fighter to take the hits and survive.  No fuel tanks, no engine, no ammunition and no pilot.  Either one of those hits, in another location, could have downed the P-36.  There is a reason Phil Rasmussen is crossing his fingers in the photo.

I have seen a photo of a Ju88 that was brought down by a single Hispano 20mm hit from a Spitfire to its tail cone.  One hit, and the medium bomber could no longer maintain controlled flight.
Title: Re: 20 mm in action
Post by: Cthulhu on January 19, 2010, 10:03:14 PM
Guys, IMO the shrapnel is the least of your worries when hit by cannon rds (except for personnel actually hit by the shrapnel of course). The real damage is done by the explosive overpressure at detonation. Sure, all those holes from shrapnel cause damage, but the real killer is the ruptured/buckled skin panels, bulkhead webs, spar webs, sheared rivets,etc. resulting from a nearby explosion. Airplanes are highly stressed, lightweight structures. There aren't many redundant parts. Punching a hole in the skin is one thing; unzipping a whole line of rivets on the upper wing skin is another thing entirely.  :uhoh
Title: Re: 20 mm in action
Post by: Yeager on January 19, 2010, 10:22:05 PM
Ive seen many pitcures of big nasty looking cannon holes where the skin is all freaked out but none of the major structure underneath is broken to critical failure.  Of course the pics are taken taken back at base after making it down safely.

This is why the .50 BMG AP had such nice effect.  Throw in a few indendiaries and there you go.  Of course throw in a 20mm like the P38 and you have a truly lethal combo.
Title: Re: 20 mm in action
Post by: danny76 on January 19, 2010, 10:22:31 PM

Great post.

But you're wrong about Ben Affleck, he'd have stuck his sidearm (probably a trusty .45) through the hole in the canopy headshotted his antagonist, scored 3 kills on is way back to the field, then quick trip to Blighty to win the Battle of Britain for the hopeless Brits.

And possibly capture the Enigma machine on return journey :bolt:
Title: Re: 20 mm in action
Post by: Cthulhu on January 19, 2010, 10:43:56 PM
Ive seen many pitcures of big nasty looking cannon holes where the skin is all freaked out but none of the major structure underneath is broken to critical failure.  Of course the pics are taken taken back at base after making it down safely.

This is why the .50 BMG AP had such nice effect.  Throw in a few indendiaries and there you go.  Of course throw in a 20mm like the P38 and you have a truly lethal combo.
The skin, especially the upper wing skin is major structure. You won't see many fighter-sized planes survive more than two or three cannon hits to the upper wing, especially near the root, and especially if he's trying to maneuver to fight or survive. Those are the guys who don't make it home to have their picture taken.
Title: Re: 20 mm in action
Post by: Pongo on January 19, 2010, 11:10:57 PM
Take the blinders off Yeager.
Its the big three ordinance failures of WW2
The sherman tank
The Mk 6 magnetic exploder on sub and surface torpedoes
and not getting the 20mm worked out as fighter armament.

In the first two the troops payed in blood.
in the last we got lucky, even though it was the easiest to solve. The freaking pony was designed for 4 hispanos.



Title: Re: 20 mm in action
Post by: Krusty on January 19, 2010, 11:43:00 PM
in the last we got lucky, even though it was the easiest to solve. The freaking pony was designed for 4 hispanos.

That's a very simplistic view on the larger issue.

Oh, BTW, the P-51 was designed for the british, that's why it could take Hispanos. US never ordered any in that configuration despite taking posession of some of the Brit production queue.

Cannons were not necessary for US success in the air in WW2. 50cals did the job well, and continued to do so until after Korea. The M2 50cal machine gun is still in service TODAY. That tells you how dependable a weapon it is.
Title: Re: 20 mm in action
Post by: Yeager on January 20, 2010, 01:19:48 AM
Its the big three ordinance failures of WW2
The sherman tank
The Mk 6 magnetic exploder on sub and surface torpedoes
and not getting the 20mm worked out as fighter armament.

Yeah, I know about the Sherman.  Im a big fan of the M26 and wish many hundreds had been made available for the invasion of Hitlers Europe and the final push against Japan as they could have been if not for the near criminal bearacracy of the Army ordinance Dept.

As far as magnetic fuses on torpedoes goes.....been there, done that.  Volumes have been written about these things.....

But the great 20mm Hispano failure?  Im not well versed on that.  

I do know the Hispanos were installed on a limited number of F6Fs and F4Us with varying degrees of success.

Of course we all know about the P38 and her well performing single Hispano supported by <gasp> four M2s...

The P-61 seemed to do just fine with her quad set up of 20mm Hispanos.  

Yet the P51 with her 4 and 6 gun M2 packages seemed to do ok, and the P47 with her smashing package of 8 M2s did pretty fair work too.  

Thats all I know.....
Title: Re: 20 mm in action
Post by: B3YT on January 20, 2010, 02:02:30 AM
of interest about the cannon V 50cal load out . which would have been lighter for the P47 8 .50 cal with ammo (380 RPG?) or 6 20mm with 120 RPG? or even 4 with 120 RPG?   

those are roughly the equivalent in fire power . it's only hypothetical . because the hurri IIc , typhoon IIb , tempest , Whirlwind, and spit Vc seemed to do quite well with the 4 X 20mm (I'll also add the spit 21 there) , and mossie. Don't forget the A36 Apache for you Americans.

If the 20mm load out  would be lighter then it would have helped with roll rate as the weight would be moved inwards on the wing needing less energy to start the roll and to maintain it. 
Title: Re: 20 mm in action
Post by: Krusty on January 20, 2010, 02:09:00 AM
A single cannon is about the equivelant of a battery of 3 50cals. M2 Cannons are much heavier than 50cals.

On top of that, only one group of P-47Ds ever flew with "425 rpg" setup and that was for ground strafing. Most (Ds and Ns too) had the "267 rpg" setup (those are in quotes because I don't know the real terms -- combat vs overload vs special load, etc). P-47M never flew with the heavy load, and probably only ever flew with 6 guns and 267 rpg.

A 4x or 6x Hispano setup like you mention, with hundreds of rounds per gun, is going to weigh anywhere from 500lbs to 1000lbs. I seem to recall doing the math regarding Hurr2a, Hurr2B, and Hurr2Cs, and coming up with about 500 lbs and change for the quad hissos there, and that's with the minimalistic ammo loadout on hurr2cs.
Title: Re: 20 mm in action
Post by: B3YT on January 20, 2010, 09:52:57 AM
ok so say 60 rpg more than enough for a fighter.  and enough for ground attack .
Title: Re: 20 mm in action
Post by: humble on January 20, 2010, 10:38:05 AM
You have to put the "failure" label for the Sherman (which I don't disagree with) within the context of designed use. The US doctrine did not actually envision "tank on tank" combat. The US intended to engage enemy armor with its TD's while US tanks supported infantry operations. So initially the issues (1942/43) have to do with deployment in conflict with doctrine and the unexpected use of the 88mm dual purpose gun in a forward deployed role. The lack of a suitable gun tube is a greater failing then anything else. If you move forward to 1944 the change in doctrine resulting in the use of the 2 "heavy" divisions changed the nature of armored combat and really enabled US achievements (at an obviously very high sustained rate of attrition). However the Jumbos suffered minimal casualties even engaging tigers and the easy 8's were reasonably capable as well. No question the M26 should have been in production much sooner but the M4 wasn't a failure as much as a 1942 tank in front line service in 1944...like saying the F4F was a failure...
Title: Re: 20 mm in action
Post by: Yeager on January 20, 2010, 10:45:59 AM
good point.  Imagine 150-200 M26s during the Normandy breakout :)
Title: Re: 20 mm in action
Post by: W7LPNRICK on January 20, 2010, 12:07:53 PM
Warning! Not a hi-Jack...when I was in Korea a very young ignorant airman thought it would be cool to bring a live 21mm F-4D Gatling gun pod round to the barracks to show his non-ammo buddies. When he had walked on the carpet for 30-40ft and reached for the door-knob {Boom! :frown:} the static spark ignited the electronic primer and removed his hand and injured several bi-standers, one of which was trying to stop him.  Remember, It's real out there.  :salute
Title: Re: 20 mm in action
Post by: Yeager on January 20, 2010, 01:18:43 PM
F4 gunpod 21mm?  Electronic primer?  Ouch!  munitions are designed to be lethal.  Treat them as such.

When I was a youngster our next door neighbor, a few years older than I, had an affection for all things containing two words "military explosive".  Since we lived near two different military installations he managed to find a live impact range and picked up two 40mm grenade duds and placed them in his coat pocket.  All it took was him jumping across a small depression in the landscape and they detonated.  Another neighbors mom was a nurse on duty at the base hospital and was part of the receiving team awaiting his mortal remains.  There was nothing could be done for the lad.  He was gutted from the sternum to the pelvis.

Title: Re: 20 mm in action
Post by: thorsim on January 20, 2010, 02:32:39 PM
one really good reason not to arm the USAAF fighters with cannons is the likelihood of FF caused by trying to kill an attacker ...

with the armor on the buffs it is unlikely that several stray .50s would ruin a bomber crew's day ...

OTOH several HE 20 or 30mm rounds likely would cause some serious problems to any aircraft ...

besides "iffin it aint broked donne feex (gon an brek) it" ...
Title: Re: 20 mm in action
Post by: W7LPNRICK on January 20, 2010, 03:05:49 PM
I'm not sure why the ammo guys called it a 21mm, all the books say 20mm. Matbe because it was distinctly different from the original 20mm anti-aircraft rounds...?
Title: Re: 20 mm in action
Post by: Pongo on January 20, 2010, 03:58:19 PM
We have indeed had some fun with this.

I can post numbers that show how much more effective pound for pound a hispano battery is then a 50 cal battery if we really want to discuss it.
Like I said earlier, it was just luck that allowed the 50 to get out of WW2 with people able to try and defend it as the primary battery of a fighter in 1944. Luck that all the enemy bombers where gone or not  able to be deployed.
The reason that the US ended up with primarily 50 cals is that they scored an epic fail at producing a good hispano, or mg 151 which they also played with. Much less matching the excellent russian 20mm.
There were many many many 1000s of unused hispanos in ware houses in the states because the army rightfully wouldnt trust it as an exclusive weapon on its fighters, but that trust is nothing to do with the hispano per say, its to do with the US version and its ammo.

As to the shermans, it is unfortunate that the Germans didnt play along with us doctrine from the battle of france time, but very fortunate that they let the British have a fully operational Tiger in 1942!!!
they used 88s in direct fire in 1940. And you dont need an 88 to easily kill a sherman, its totaly vulnerable to 75mm L48 fire. Its vulnerable to 50mm L60 fire!
Comparing the failure of the Sherman to the Wildcat is like saying the hellcat wasn't made. Not only was it made, it was designed made BEFORE its tiger showed up so to speak.
Similarly, its not that the Shermans Hellcat wasnt attempted, it was worked on in 1941. But the technical politics and infighting sabotaged it just like the hispano and the torpedo.

And it is mostly only tragic in comparison to the excellence of design and integration we see from so many US war fighting equipment.

To say the 50 was preferred as a fighter battery to any 20mm is like saying that the Dauntless was preferred to any dive bomber, just because it was preferred to the Helldiver.

I am not saying the 50 was a failure, it worked. Its deadly, but the development of a US 20mm fighter gun was a complete failure. And its not that it wasn't wanted or tried. And that is starting with a fully functional product!

Title: Re: 20 mm in action
Post by: Karnak on January 20, 2010, 04:11:05 PM
The US manufacturer of the Hispano built it to artillery tolerances because it was a "cannon" and that caused a lot of its problems.  They also refused to adopt the British solution to the jamming issue.  I recall reading the conclusion of a British report after testing the US made Hispanos.  They said the finish on it was much better than the British Hispanos, but that it suffered such a high stoppage rate as to be totally unsuitable for service, something like ten or twenty times the stoppage rate of British made Hispanos.
Title: Re: 20 mm in action
Post by: Yeager on January 20, 2010, 04:19:31 PM
As long as they work flawlessly in game I'm good with it  :rock
Title: Re: 20 mm in action
Post by: smoe on January 20, 2010, 05:06:03 PM
I've seen gun camera views of 109/190's having half there wing blown off. I've always wondered if this was due to a secondary explosion like 20mm rounds or fuel tanks exploding inside the wing after taking hits from 50cal's.
Title: Re: 20 mm in action
Post by: Pongo on January 20, 2010, 06:25:50 PM
There is no fuel in the wings of either plane. So its ammo, or as some have attested on these pages in the past, the airstream forcing through a single 50 cal hole causes the wing to explode like a balloon.

The hispano mk5 weighs 42 to the 50s 29 pounds. An evolved design to be sure, but nothing exotic, it is just made to not last as long.
US manufacture of the Hispano in WW2 was arround 135000 units. Most never used.
Title: Re: 20 mm in action
Post by: Krusty on January 20, 2010, 11:09:28 PM
one really good reason not to arm the USAAF fighters with cannons is the likelihood of FF caused by trying to kill an attacker ...

That's a retarded comment
Title: Re: 20 mm in action
Post by: Widewing on January 20, 2010, 11:21:48 PM
The skin, especially the upper wing skin is major structure. You won't see many fighter-sized planes survive more than two or three cannon hits to the upper wing, especially near the root, and especially if he's trying to maneuver to fight or survive. Those are the guys who don't make it home to have their picture taken.

Robert Johnson's P-47C absorbed twenty one 20mm hits and over two hundred 7.92mm MG rounds. He flew it 200 miles back to Manston. Hits in the wings, fuselage, tail and engine. It boiled down to luck, and one very strong aircraft.


My regards,

Widewing
Title: Re: 20 mm in action
Post by: thorsim on January 20, 2010, 11:25:50 PM
yea ok ...

That's a retarded comment

not only did they not need shoot down big 4 engine heavily armored bombers,
they didn't want them to shoot them down ...

Title: Re: 20 mm in action
Post by: BnZs on January 20, 2010, 11:51:23 PM
Anyway you look at it, a given number of Hispano rounds is going to weigh more and take up more volume than the same number of .50 cal rounds. You'll get more firing *time* or a denser "pattern" for the same weight of ammo, which is an acceptable advantage if your weapon is deemed lethal *enough*. Kind of like the difference 5.56 and 7.62mm...some argue for the heavier punch of the latter, some argue that 5.56 has "enough" punch and you can carry more ammo.

And when it comes to engaging fighters, we have different priorities. In AHII, we are dogfighting, taking snapshots at all sorts of bizarre angles. In the war, most kills involved pulling in behind and hosing the opposition down liberally at close range and little deflection. Further, our mission requirements are different. Say you're escorting bombers...you pull in behind an intercepting 109 and hose it down. Smoke and glycol pour from the plane, it dives for the clouds and disappears. Even if you only get to claim a "probable", mission accomplished, that 109 is no longer threatening the buffs. In AHII however, you want to actually knock the darn wing off or the like, so that you get a kill immediately and your bandit does not land, ditch, or get shot and the system awards the kill to someone else.
Title: Re: 20 mm in action
Post by: Pongo on January 21, 2010, 12:42:32 AM
Lets seem some shots of what that jug looked like with 20 20mm rounds in it.
I have read and heard the story too, I would like to see shots equivilent to the p36 ones.

Its really really easy. The hispano is 3 times better then the 50 cal at shooting down aircraft, but only weighs twice as much. With a simular rate of fire and balistics, a given small number of hits will much more likely destroy the aircraft that you are shooting at. The game reflects the difference very well.
If there was a pony in AH with 4 hispanos and the one with 6 50s, How many sortis would the 50 cal one get?
There are logistical considerations, the 50 costs less, the 50 is easier to work on, etc.
But for all the reasons you put an automatic weapon on a fighter, the hispano is far more effective.
Unless you are comparing the US hispanos. Then if you factor in the jams over a thousand missions. The number of stoppages will make the 50 cal more effective. Probably way way more effective. So that is what they went with.

And the hispanos sat in ware houses.

And there were more then enough 50 armed planes shooting at vulnerable and smaller planes with good enough marksmanship to win the war quite effectively.
Until the kamakazis, then they wanted 20mm. How many men died to the kamakazis, How many would have died if all the hellcats had 4 effective 20mm instead of 6 50s?
How much quicker would the LW been attrited? Even a month is lives. Thousands of them.

So its not nothing. And they could clearly see in that P36 what the situation was. They tried to adopt one of the best 20mm in the world, and they failed. For absolutely no good reason.
Its stunning that they failed, just like the torpedo, and the medium tank. Although the torpedo gets the gold ring for biggest tragedy. The sherman really was a great tank in 1941-42. And the 50 worked great for what it was. And still does. But its no Hispano.
Title: Re: 20 mm in action
Post by: Charge on January 21, 2010, 09:04:49 AM
Alleged 20mm damage pictures:

http://www.aircrewremembrancesociety.com/raf1943/buck.html

http://upload.wikimedia.org/wikipedia/commons/c/c2/Shvak_bf109.jpg

20 or 30mm, who knows...
http://4.bp.blogspot.com/_kIWY2DV0KnE/SIPq0VClCgI/AAAAAAAAA4I/-9MekvU5Vxs/s1600-h/Sperry+Retractable+Ball+Turret+showing+direct+hit+by+cannon+fire.jpg
http://bayourenaissanceman.blogspot.com/2008/07/weekend-wings-25-air-gunners.html

Also could be 20 or 30mm:
http://b24.net/crashsites/42-95025%20damage%2015Jun44.jpg

-C+

Title: Re: 20 mm in action
Post by: Demetrious on January 21, 2010, 09:25:05 AM
And the hispanos sat in ware houses.

This is blatant BS. I demand at least a few references.

Quote
They tried to adopt one of the best 20mm in the world, and they failed. For absolutely no good reason.

This is also blatant BS. The Hispano cannon, for it's entire service life, was always a royal pain in the ass. Even the Russians commented on how much of a pain in the bellybutton it was compared to their own 20mm cannons- they pulled the Hispanos out of their lend-lease Hurricanes and stuck their own weapons in. In fact, their own 12.7mm machine gun was lighter then the .50 browning and had a greater rate of fire, too. The intense difficulties presented by manufacturing the Hispano is what kept the US from deploying them operationally, and why the C Hog armament was discontinued.

Quote
Its stunning that they failed, just like the torpedo, and the medium tank.

If the king of the battlefield was the Germans and their DAS UBERTANKEN, then why did they field so many Panzer IVs? Which- just like the Sherman- received periodic upgrades throughout the war. The Panzer IV was the German's principal tank for most of the war, and the Sherman was more then a match for it. As far as heavy/assault tanks go, we had the Jumbo Sherman, and we could also count on British Cromwell's to fill that role in joint operations. The inferiority of the Sherman is, and always has been, an overblown myth.

Quote
The sherman really was a great tank in 1941-42. And the 50 worked great for what it was. And still does. But its no Hispano.

For fighter vs. fighter combat, I'd take a six .50 cal battery any day. Why? Because the Germans- nor the Japanese- had a fighter that could stand up to six, or even four .50 cals. There is ammunition capacity to consider- 20mm shells were larger volume-wise, you could only carry so many. Consider the cannon ammo capacities of most of the cannon-armed fighters of the war. And since it only takes a few rounds in the engine- or one in the pilot- to destroy an enemy aircraft, the cannons are frankly overkill. I'd rather have greater fire duration. The freedom to hose around .50 cal is highly useful when you're fighting against enemies that only take a few rounds in vital spots to down- and given the way wing-mounted guns tended to spray rounds around, the chances of a few .50s striking a vital area were excellent.

Cannon armaments were important for air forces engaging heavy bombers, but since the US wasn't, they didn't need them. They had the Brownings, and with their excellent ballistics, they proved effective and powerful weapons. People only complain about them in AH because it's possible to take a Warhawk up against something like a P-47 or a Hog, which can soak amazing amounts of damage.
Title: Re: 20 mm in action
Post by: 63tb on January 21, 2010, 10:45:40 AM
This is from Tony William's site regarding the US attempts to produce the Hispano 20mm -


http://www.quarry.nildram.co.uk/US404.htm



63tb
Title: Re: 20 mm in action
Post by: Demetrious on January 21, 2010, 11:08:04 AM
This is from Tony William's site regarding the US attempts to produce the Hispano 20mm -


http://www.quarry.nildram.co.uk/US404.htm



63tb

Tony Williams is a regular over at ww2aircraft.net and his forum contributions are always informative.
Title: Re: 20 mm in action
Post by: Pongo on January 21, 2010, 11:15:42 AM
References to what?
How many Hispanos were made in the US during the war. Flying Guns says 135000. To how many you need to use to put 4 in each P61, 2 each on the Helldiver, 4 each on a few pony derivatives, 1 each on the P400 and the P38? Of americas hundred thousand, how many Hispanos would you say were used? Where do you think they went?

I said the Hispano was one of the best cannons in the world because it was. That the soviets had a better one doesn't not make the Hispano one of the best.  The soviets had a better HMG as well, that doesn't stop the 50 from being one of the best either.You can rest assured, the americans didn't have a better one available and it worked fine in its British derivative. That you think the hispano was discontinued is interesting. It was the primary armament on all of the last generation of navy prop fighters(bearcat, corsair, tigercat, skyraider). It was the primary weapon on the first generation of navy jet fighters.
Only the end of ww2 design jet planes like the F84 and F86, designed arround a 50 cal, kept it, and they regretted it. They struggled to replace the 50 in an airframe that was not designed to take such a long weapon.In the end the Hispano was tremendously effective in US service. Why do you think that is?

The germans were not happy with the Panzer IV either, They were not happy with its armour lay out, its mechanical components, they were not happy with the size of the road wheels. The Germans had battle field and economic constraints that precluded them totally replacing it. They wanted to cut bait with it in 1942... But they were very very happy to have their "uber tanks" as you call them. Those "uber tanks" are in size and capability very similar to the tanks the US and Britian started makeing when the guys who watched their units whiped out by tigers and panthers got some say in what the tanks that they were issued should be. Instead of interwar calvary guys deciding. The US in fact designed and fielded tanks that make your Uber tigers look small. Why did they do that?

It is understandable that pilots in the field, having had good success with the 50 cal would say it was enough. Had they flow the same plane with well implemented hipspanos they would have had the same opinion on them that people in AH do. That the first pilots(experienced 50 cal pilots) that shot down planes with the C Hog had, And the first typhoon pilots had when they unleashed that battery.

 But the reason that probably 90% of 1945 US fighters didn't have hispanos, is that the people in charge of converting them for US production totally failed to do so effectively. Had they, you would have some interesting insults for people who maintained that the 50 would have been sufficient.

The people in AH have the same opinion of the 50 and hispano that ww2 people had. They could get the job done with 50s. The examples I gave of the impact of kamakazi attacks is just historical fact. Everything I have said of the intent and desire to produce the hispano and adopt it for wide spread US use is just simple fact.

All you are left with is a statement of about the equivalent of "real men don't need cannons"
Title: Re: 20 mm in action
Post by: Pongo on January 21, 2010, 11:28:00 AM
Tony Williams is a regular over at ww2aircraft.net and his forum contributions are always informative.

I have his Flying guns ww2 book and his firepower book. I have read the book he quotes written by the guy who adapted the french 20mm for the RAF. I had exchanges with him about that very book just recently.(I note he has added new purple quotes from that very book to that page.hmmm)

Do you read anything in that excellent post that discounts what I say about a failure to adapt the effective british hispano to US use in a timely manner. Do you find anything in that post or his books to support your apparent contention that the development of the US hispano in time for ww2 was not a failure, it was just something that wasn't wanted?

The conversion of the Hispano, from an engine mounted magazine fed specialty cannon to a wing mounted, belt fed cannon was not trivial, But most everything had been done by the Brits after they failed to get it working effectively in time for the Battle of Britian even though they started in 38?

Title: Re: 20 mm in action
Post by: Pongo on January 21, 2010, 11:38:49 AM
"I'd rather have greater fire duration. The freedom to hose around .50 cal is highly useful when you're fighting against enemies that only take a few rounds in vital spots to down- and given the way wing-mounted guns tended to spray rounds around, the chances of a few .50s striking a vital area were excellent. "
this is just incorrect. I could and did lead to many claims that were not kills. Especially against german planes. That AH allows you do to do this is a game weakness. The guns would overheat and loose accuracy if treated this way. This is a major advantage in real life of the hispano over the 50 and the 50 in turn over the 30.  Being able to kill with way shorter bursts, because shorter bursts are far less likely to adversely effect the guns.
Title: Re: 20 mm in action
Post by: Karnak on January 21, 2010, 12:52:17 PM
One thing that struck me, reading the article about the P-36s at Pearl Harbor, was how many of the claimed kills of Japanese and American fighters were false.  I am not really familiar with the P-36's durability, but I know the A6M2 was not protected at all and yet only one A6M and one P-36 seemed to actually be valid kills, even though the .50 cal armed P-36s succeeded in hitting quite a few A6M2s.
Title: Re: 20 mm in action
Post by: Pongo on January 21, 2010, 01:49:38 PM
I read a great write up on how Japanese over claiming might well have really impacted the battle of Guadalcanal. All counties over claimed of course. But the Japanese penny packeted the attacks at cactus, because it was so far, and because they thought they had repeatedly wiped it out.
We can presume that a P36 is in the same range as a P40 for robustness. Its now F4F-4 but obviosly a pretty hardy plane. I do not know if that one would have made it home if it wasnt almost over its base and fighting Zeros that were almost all ammo expended already.
Have you read "The first team" series Karnak? If you haven't you must. Fantastic books.
http://www.amazon.ca/First-Team-Pacific-Combat-Harbor/dp/159114471X/ref=pd_sim_b_1 (http://www.amazon.ca/First-Team-Pacific-Combat-Harbor/dp/159114471X/ref=pd_sim_b_1)
Title: Re: 20 mm in action
Post by: Karnak on January 21, 2010, 02:14:54 PM
Nope, I haven't.  I'll have to look into that.

Interestingly, in that article, the P-36 you showed photos of was not claimed as a kill by the Zero pilots who hit it.
Title: Re: 20 mm in action
Post by: Wmaker on January 21, 2010, 02:23:10 PM
We can presume that a P36 is in the same range as a P40 for robustness.

Yeh, the airframe is basically as in the P-40B with minor differencies. P-36 was stressed for 12Gs (!!!) at 2500kg weight. While the weight is rather low compared to P-40B's normal take off weight for example, and it doesn't directly apply to enduring battle damage, it still tells us something about the airframe's robustness IMO.
Title: Re: 20 mm in action
Post by: W7LPNRICK on January 21, 2010, 11:54:00 PM
Yeh, the airframe is basically as in the P-40B with minor differencies. P-36 was stressed for 12Gs (!!!) at 2500kg weight. While the weight is rather low compared to P-40B's normal take off weight for example, and it doesn't directly apply to enduring battle damage, it still tells us something about the airframe's robustness IMO.

sounds like a good candidate for AH hangers.   :salute
Title: Re: 20 mm in action
Post by: Pongo on January 22, 2010, 01:43:51 AM
Nope, I haven't.  I'll have to look into that.

Interestingly, in that article, the P-36 you showed photos of was not claimed as a kill by the Zero pilots who hit it.

to me it looks like it must have been a pretty steep deflection shot.
Title: Re: 20 mm in action
Post by: Demetrious on January 25, 2010, 08:47:04 PM
sounds like a good candidate for AH hangers.   :salute

It would be, actually. If the Brewster could make it, the P-36 would do fine too (which was also used by the Finns in the Winter War to good effect.) It's already in WWII Online and holds it's own against early FW-190s and Emils.
Title: Re: 20 mm in action
Post by: Saurdaukar on January 26, 2010, 09:07:37 AM
to me it looks like it must have been a pretty steep deflection shot.

+1