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#51
August 19th 03, 03:05 AM
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"Emmanuel Gustin" wrote in message ...
"Kevin Brooks" wrote in message m... Your own website on this subject indicates that the total kinetic energy available in a P-47's fully loaded weapons dwarfs that available to the Tempest (add up the available kW for each, based upon full ammo load, and you will see what I mean). It is about 50% more -- but then, the guns and ammunition of the P-47 also weighed 64% more! The P-47 could have carried, for a similar weight as its eight .50s, six Hispano cannon with 200 rpg, instead of four. Such figures simply indicate that the RAF was satisfied with a lower ammunition capacity than the USAAF; willing to sacrific combat endurance for lower weight. In fact, if maximizing "stored muzzle energy" is your goal, the 20 mm would still be a better choice than the .50. The 20 x 110 round delivers about 48 kJ (45 kJ in the shorter- barreled M3 and Mk.V guns) and weighs 257 gram; the 12.7 x 99 round delivers 17 kJ and weighs 112 gram. For the same weight, you can store more energy as 20 mm rounds than as .50 rounds. I used muzzle energy because it was what was available; the more telling figure would be the remaining energy at typical CAS/BAI engagement range (and I'd think that would tilt even more heavily in favor of the .50 cal, as it did not bleed velocity as quickly as the 20mm). Yeah, there is the factor of the explosive filler in the 20mm, but then again there is the consideration that a fair number of them were duds, and in the CAS/BAI role a lot of them would have been wasting their explosive yield after burying themselves under dirt cover 9and it would not have taken much cover to render that meager 20mm filler quantity moot). One of the driving factors towards larger calibre is, quite simply, efficiency. Look at the Typhoon Mk.IA: That dozen .303 guns did not quite match a single 20 mm for firepower. Careful, or you'll end up with a hypothesis that says, "Bigger is always better, so the best aircraft armament was the....37mm!" Or do you have a cut-off for where that bigger equals more efficient no longer applies?  It also says that the .50 cal was not "deficient" during WWII. It says, or at least I intended it to say, that the .50 was sufficient provided enough guns were installed and the target wasn't too sturdy. "However, the .50 remained a reasonably effective weapon against fighters and the lighter bombers, if enough guns were installed; usually six in American-built fighters. Only during the war in Korea the .50 was clearly proved to be deficient in destructive power." I get your drift here regarding the target characteristics--but allied aircraft were not facing tremendously sturdy adversaries in the air-to-air role in either theater (Pacific or Europe). The gist of this thread (at least began) in regards to the CAS/BAI role--and I can't see where anyone can say that the 20mm was proven to summarily exceed the performance of the .50 cals in that regime either. That's a far cry from saying that the .50 was the best possible choice. For gosh sakes, I am not saying that! I said that there was not enough difference exhibited during WWII service, in terms of terminal performance (i.e., its performance in the CAS/BAI role), to pronounce it decidedly inferior, or for that matter superior, to the 20mm! Another poster claimed that the 20mm was the decidedly superior strafe/CAS/BAI weapon in comparison to the .50 cal during the war--I don't think there was enough of a real difference exhibited in operations to support that. Brooks The .50, like many other US weapons of WWII, corroborated Stalin's dictum that quantity has a quality of its own. It's quality was not its performance, which was average by WWII standards -- not even surprising for a gun that was of relatively old design -- but in the fact that it was a decent, very reliable, mass-produced weapon; and that it was widely standardised, a very important consideration for a rapidly expanding force. 
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#52
August 19th 03, 03:59 AM
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Subject: P-47/51 deflection shots into the belly of the German
tanks,reality From: Greg Hennessy Date: 8/18/2003 5:16 PM Eastern Daylight Time Message-id: On Mon, 18 Aug 2003 21:46:50 +0200, "Emmanuel Gustin" wrote: The P-47 could have carried, for a similar weight as its eight .50s, six Hispano cannon with 200 rpg, instead of four. God help the FW190/BF109/Zero on the recieving end of that. greg -- $ReplyAddress =~ s#\@.*$##; # Delete everything after the '@' Alley Gator. With those hypnotic big green eyes Alley Gator. She'll make you 'fraid 'em She'll chew you up, ain't no lie My dad said the 50's worked but the 20mm's often didn't
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#54
August 19th 03, 07:45 AM
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(Lisakbernacchia) wrote in message ...
My dad said the 50's worked but the 20mm's often didn't Certainly true when it came to US guns. The Browning was very reliable, but the US-made 20mm Hispano had all sorts of problems. See: http://www.quarry.nildram.co.uk/US404.htm for the full, painful story... Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk Military gun and ammunition discussion forum: http://forums.delphiforums.com/autogun/messages/
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#55
August 19th 03, 07:55 AM
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(Kevin Brooks) wrote in message . com...
Careful, or you'll end up with a hypothesis that says, "Bigger is always better, so the best aircraft armament was the....37mm!" Or do you have a cut-off for where that bigger equals more efficient no longer applies? There are two separate issues he efficiency, and optimum performance. Efficiency is simply a matter of power-to-weight ratio, in terms of the energy (kinetic and chemical) delivered for a given installed armament weight. Cannon have a general advantage over MGs because of the added chemical element, but bigger cannon are not necessarily better: the USAAF's 37mm M4 was very inefficient (less than the .50 Browning), mainly due to its low rate of fire. Optimum performance is a balance between hit probability and destructiveness. On one extreme, you have the few RAF fighters equipped with twelve .303s; very high hit probability, negligible destructiveness against tough targets. On the other you have those German bomber-destroyers equipped with one 50mm cannon; not much chance of scoring, but one hit should do the trick. The optimum choice varied depending on the circumstances. HMGs like the .50 were fine against smaller and/or less protected targets, 30mm best against tough heavy bombers. A battery of 20mm proved to be the best all-round compromise. Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk Military gun and ammunition discussion forum: http://forums.delphiforums.com/autogun/messages/
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#56
August 19th 03, 12:56 PM
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#57
August 19th 03, 09:10 PM
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(Lisakbernacchia) wrote in message ...
Subject: P-47/51 deflection shots into the belly of the German tanks,reality From: (Tony Williams) Date: 8/19/2003 2:55 AM Eastern Daylight Time Message-id: (Kevin Brooks) wrote in message .com... Careful, or you'll end up with a hypothesis that says, "Bigger is always better, so the best aircraft armament was the....37mm!" Or do you have a cut-off for where that bigger equals more efficient no longer applies? There are two separate issues he efficiency, and optimum performance. Efficiency is simply a matter of power-to-weight ratio, in terms of the energy (kinetic and chemical) delivered for a given installed armament weight. Cannon have a general advantage over MGs because of the added chemical element, but bigger cannon are not necessarily better: the USAAF's 37mm M4 was very inefficient (less than the .50 Browning), mainly due to its low rate of fire. Optimum performance is a balance between hit probability and destructiveness. On one extreme, you have the few RAF fighters equipped with twelve .303s; very high hit probability, negligible destructiveness against tough targets. On the other you have those German bomber-destroyers equipped with one 50mm cannon; not much chance of scoring, but one hit should do the trick. The optimum choice varied depending on the circumstances. HMGs like the .50 were fine against smaller and/or less protected targets, 30mm best against tough heavy bombers. A battery of 20mm proved to be the best all-round compromise. Even if they didn't work too well I guesss you never flew I wouldn't want to have flown a plane fitted only with American Hispanos, but fortunately there were very few of those. British Hispanos, or German MG 151/20s, were a different matter. Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk Discussion forum at: http://forums.delphiforums.com/autogun/messages/
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#58
August 19th 03, 11:39 PM
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In message , Kevin
Brooks writes "Paul J. Adam" wrote in message ... Fit for purpose. The cost of stopping the line, debugging a notional F6F cannon armament, securing sufficient cannon, ensuring supply of spares and parts, and managing multiple supply lines outweighed the benefit of upgunning the Hellcat. And why the Bearcat entered into production in 45 with MG's...? And why it was regunned with 20mm? (You have a point, though, the switch happened later than I thought) Why were the first Hawker Typhoons armed with .303 MGs? Because that was the quickest way to get a new type flying. The armament on the Corsair changed between prototype and production machines--why do you suppose, if the USN was not happy with the .50 cal, this did not happen with the F8F? Then why did they change to quad 20s, if 4x50" was perfectly sufficient? For night raids with incendiaries? Gunners are useful as lookouts rather than killers. Yes, even for those night raids. My father, still alive and kicking, performed night raids with incendiaries, and yes, they had their guns onboard. If you think it was as widespread as some pubs would have you believe (though as best i can determine most of those pubs merely mention Lemay's (in)famous decision and *assume* that is what followed), why can't we find very much evidence of this in crew accounts from various units? Jumping threads, for night bombing I'd have binned the mid-upper turret on the Lancaster and Halifax, and put 2 or 4 .50s in the tail (possibly with two crewmen, doing shifts to keep their alertness up). For day bombing, I'd have kept single calibres in each turret, but fuselage guns get .50 and the tail gets twin 20s. I'd think the MG, regardless of our differing views on its fighter usage, would have been a better choice for a bomber, especially in a night role. The .303 was really too light, even in quadruple batteries, and the 20mm too heavy for convenient flexible mounting. The .50 was a good compromise: decent weight of fire, adequately destructive projectile, available with 'headlight' tracer for deterrent fire, and light enough to be put in power-operated turrets. 20mm for fighters, .50" for flexible guns Fleeting targets with a generally closer detection range would I think be better handled by high volume of fire (and even you would agree that it is easier to carry a few hundred rounds of .50 cal than it is an equivalent amount of 20mm) as opposed to placing emphasis on hitting power. Bombers didn't have ammunition problems, as a rule: Lancasters carried about _two thousand_ rounds of .303 for the tail guns - each! 99% of missions fired less than 250-odd, which is 150rpg of cannon ammo if you've got quad 20s aft. Also, the M2 didn't fire any faster than a Hispano. Trouble is, the Hispano wasn't easy to mount in a turret, and Same reason the Typhoon was first produced with twelve .303 guns - "what was available to get this thing flying". For heavens sakes, we changed the armament fit for the Corsair during the period between prototype and production (and I would bet we can find others where similar changes were made). Are you thinking the rush to get the Bearcat into operations in 45 was somehow more intense than getting the Corsair into service earlier in the war to replace the likes of Buffalos and Wildcats?! If the Bearcat was so great with fifty-cals, why were most produced with cannon? Why go through the hassle of change? Hey, I am not arguing that the USN started its shift to the 20mm (though I was surprised to see they predated the USAF in this regard to the extent they did), I was pointing out that the USN did not up and decide that the .50 cal was a decidedly inferior armament to the 20mm, as you seemed to say in the initial exchange that started this thread. 20mm was superior enough to be worth changing over. Doesn't make the .50 "useless", just less efficient at turning payload into carnage. Except that comparing typical batteries, you're comparing two 20mm to three .50" rounds. You seem to have this notion that the M3 .50 arrived in 1942 - it was a postwar innovation. In terms of CAS/BAI use, which this was all about (don't know how/why we shifted off into the air-to-air...), an examination of the .50 cal versus the 20mm could lead to several conclusions. I believe I pointed out that the typical full weapons load on the P-47 with its eight MG's, in terms of total kW of power involved, dwarfed that of the Tempest with its four Hispano V's. Hey, by that argument the Lancaster's huge ammo load for the tail guns made it _lethal_. How many rounds were fired, with how much energy, in a typical firing pass? Carrying more rounds gets you more firing passes, but doesn't increase the lethality of each pass. Now, I don't think that means that the P-47 was *better* than the Tempest in the CAS/BAI role--I just think it means that you cannot out-of-hand discount the .50 cal as being inferior in those roles (and against the types of targets that both were engaging in that conflict) to the 20mm. Certainly when the US AC-130s did some comparative trials against truck targets, 7.62mm was found to be basically useless: 20mm very effective if fired from low enough for reliable fuzing (flying above 37mm range meant many rounds tumbled before impact): and 40mm was good but not infallible. Was the US or UK pattern of bayonet superior in close combat? Where's evidence to prove it one way or another? Exactly; they were both effective in their role (for what little use they saw in actually sticking people). You have not seen anyone claiming that either was definitely superior, have you? Actually, I've had a US enthusiast get very abusive about the "provable uselessness" of the British spike bayonet of the period, but that's by the by. Not even "one was better than the other, but both worked". (And no, he didn't have any _evidence_, or even any analysis, he just didn't like the look of the British bayonet) CAS/BAI aircraft used their guns after their primary ordnance was expended. Guns were used after the primary weapons were expended. Not necessarily. I believe that, like today, it would depend on the nature of the target engaged as to what particular weapon was used, and when. As a rule, you'd use primary weapons first, with guns used if repeat passes were feasable. The aerial rockets of the day were rather effective, but accuracy was not always their best suit. Whereas guns were accurate but lacked lethality against anything hardened, and also were essentially point weapons. Typhoon pilots (4x20mm, apart from a few with 12 x .303") would fiercely argue that point. Then why was the RAF so happy to use the P-47 through the end of the war? Because it was a really good aircraft, even if its gun armament was not quite optimal. Was the original M1 tank a failure because it was armed with the L7 105mm gun, rather than the later 120mm? Did the first few thousand Abrams crews weep bitter tears because they only had a combat-proven 105mm gun instead of a 120mm? For the same weight of guns and structure, the P-47 could have hauled six 20mm into battle. Or four guns, and more of its primary weapon (bombs, rockets and fuel... loiter time matters a lot for CAS) It about doubled the amount of energy that it could bring to bear on a targets, No, that's a function of ammunition storage. Eight .50s put about half the energy on target of four 20mm guns for a given firing pass (which is limited by time not ammunition) While the P-47 carried a lot of ammunition, it needed twice the armament weight to do so. A P-47 with 4 x 20mm could have made more firing passes for the same weight, or delivered the same destructive energy and had some weight over. The Germans after 1918 determined that the Kar98 rifle was "darned effective". The US decided that a five-shot bolt-action rifle was lacking, and produced and fielded the M1 Garand. (The UK looked at alternatives but refused to pay for them) Sitting on your laurels gets you in trouble. That's the trouble with having a capable weapon that's been surpassed (think the Lee-Enfield in 1938 or so). Yes, it's got superb history; it went on to win a war. But was it really the best possible option? Or would we have done better had we selected a .280" short-case selective-fire rifle in 1936? Different weapons, different characteristics in comparison (i.e., rate of fire), and different target sets. I don't see the link to the .50 cal vs. 20mm issue. The US had a really, really good .50 MG at the end of WW2. Good against aircraft, against tanks, against people, against pretty much anything it was fired at. By 1941 it was no longer an antitank weapon but it was still very effective in all sorts of roles. That selfsame Browning M2 (albeit in a modified form to improve the barrel change) is _now_ in service with the British Army, adopted about seventy years after the US took it on board. Not by the USN, though, who were selecting existing 20mm weapons over existing .50" guns.. And they were killing very few Migs with those 20mm's... Out of how many engagements? The figures I'd like are the numbers of times aircraft got MiGs under the pipper and fired, and the numbers of kills. The USN had picked 20mm by 1945. Really? Then why was an aircraft that entered production that year still carrying the .50 cal's? Why were most produced with 20mm? How many P-47 sorties? How many A-36 sorties? I have no idea. Nor do I care. The fact is that the A-36 and P-51 did fly CAS/BAI, though obviously not as often as the P-47 which formed the backbone of IX TAF, etc, in that role. By that argument the B-24 was a CAS/BAI aircraft, although it didn't fly many such sorties. Hey, the C-130 is an anti-shipping striker, it flew a couple of such sorties in 1982... Yep. What is easily forgotten today was that Korea was a peripheral concern for the West. The threat was on the Central Front in Germany and _that_ was where effort was focussed: Korea got what could be spared. Nobody was going to pay to re-gun WW2 leftovers for fighting in Southeast Asia. Didn't we do exactly that, and more, with the B-26 Invaders? Not particularly, considering they were being withdrawn by war's end. They were used because they were available, and the best was made of what was spared (stories of aircrew shovelling tacks out of the bomb-bay during 'Operation Strangle' in hope of bursting NK truck tyres come to mind - brave, but not the mark of a really co-ordinated campaign) Because it was the best possible weapon? Or because it was fitted to the available aircraft? When did Korea ever get first call on forces? (The F-84 saga is a great example) With the F-86 it seemed to. With the F-84 it certainly wasn't, and Korea was thoroughly behind Europe and the US in terms of supplies of new-model aircraft. With the F-86 the shortage of numbers is indicative. The US could have blackened the Korean sky with aircraft... except for other commitments elsewhere. Your assumption, not mine. If you found yourself in combat armed with a .38 Special rather than a .357 Magnum, would you insist on being pulled out of battle to be re-armed, or would you fight on with what you had? Come on--re equipping of units was *continuous* during the Korean War. When improvements were available. Improvements were implemented in the field as well (see the history of the large capacity drop tanks on the F-80's). Changing fighter armament isn't a field mod unless explicitly designed in, especially not on early jets with their sensitivity to gas ingestion. That's because you insist on seeing matters as "because the 20mm is better, the .50 must be useless". And that just is not so. The .50 is a good weapon; just not the best. And the 20mm of WWII can be claimed, hands-down, as being the "best"? Depends. For shredding unarmoured Japanese aircraft? I'd toss a coin for most missions, vote 20mm for killing Kamikazes. For shooting at Luftwaffe fighters? Probably the 20, but the Browning will have adherents. For strafing? Explosive payload is a significant edge. For shooting at armoured bombers? 20mm is really too small and .50 is useless (but that was never an Allied mission). Is it _so much_ better that I'd order a switch from something that worked quite adequately, is in universal service, and has a huge user base, in the hope that the replacement's theoretical advantages proved real? Probably not, especially if the replacement was proving unreliable (as the US Hispanos were). The USN decided to move to 20mm regardless (certainly on the SB2C) despite the negatives. After all, the UK went from .303 to 20mm without an intermediate step, which might colour thinking. The US discovered .30 was of limited value, but had a very good .50 available and a co-operative target set. I don't think so; I 'd give them parity. Just don't see it. The 20mm fires at the same rate, with the same velocity, with a much more destructive projectile. If the .50 really offered parity, why weren't the F-100 and F-8 armed with six .50" guns? (In the case of the F-8, which had persistent gun problems, that might have even been a good idea) What's the cost of changeover? Consider changing production for the F6F - you now need two armourer streams, two training streams, twice the spare parts, two ammunition pipelines, two parts chains... Exactly what occured with the Corsair and the Bearcat anyway--so why would this have been a great issue? Because it _was_ an issue? Case-by-case judgement. Evidently worth forming some specialist Corsair units, regunning the Bearcat, but not worth changing the Hellcat yet. From the OA of that conflict. Missess are still relevant because very few pilots shoot to miss. You fire when you think you'll hit. If you hit and don't kill... that's bad news, as bad as firing and missing. . The .50 was able to hit, but had trouble killing, MiG-15s. And the performance of the 20mm? Not many 20mm kills were registered, IIRC... How many 20mm shots were taken? The Navy's jets were relatively few in number and lacking in performance, but how many firing opportunities did they turn into confirmed kills compared to Sabres? Shades of Linebacker II: while the USAF complained that "lack of guns was the problem" and achieved around a 2:1 kill ratio, the wholly gunless USN achieved 6:1 and persuaded the NVAF that the Air Force were easier marks. In raw kills, the USAF killed more, but they were a lot less effective doing it. (Lots of factors: pilot training, weapons maintenance, doctrine, tactics... post-war often hidden under a mantra of 'we needed more guns' ) With extra weight of guns and ammo, invalidating the comparison. Hey, the 47 carried more guns--is that a crime? More guns and more ammo means more weight. In this case, about six hundred pounds more weight. That's weight not usable for other weapons, fuel, pilot armour, or just extra agility (lighter for the same horsepower). If I load a three-quarter-ton 'mission package' into your favourite NASCAR racer, am I handicapping its performance if the same package in other cars weighs less than half a ton? maybe that was one reason it was considered by many to be more effective than the Tempest... The P-47 was considered better than the Tempest? Source for this? (I can see it competing very well with the Typhoon. But the Tempest?) Interesting that the 'standard' 6 x 50" battery is disregarded and we're now into comparing a "six fifties-equivalent" cannon with "eight fifties". You were the one who brought up europe versus the Pacific, right? And you seem to find that the Tempest was a better CAS/BAI gun platform than the eight-gun P-47...or not? Yep. And the P-47 still puts half the energy downrange of a quad-20 armed fighter, for the same burst length. So, when was the last time a frontline fast-jet chose .50 over 20mm? Strawman. We were talking WWII strafing operations, weren't we? before we got sidetracked into Korea? Okay, then the USN evaluated strafing weapons for their new divebomber (which would do noticeable amounts of strafing) and picked 20mm over ..50cal. I agree completely. The US Navy also agreed and put 20mm in all its new production. The USAF stuck with .50" and found it lacking in battle (else why switch to a larger calibre?) Uhmm...it seems that the USN was still quite satisfied with the .50 cal during WWII, enough so that it had that armament included in fighters produced during the closing months of the war. That they thought they could increase their hitting power by shifting to the 20mm is evident, and yes, they began that shift as the war closed--but they apparently were still quite happy with the .50 cal MG. So why switch, if .50 was just as good? You say it was no better air-to-air and no better air-to-ground - so changing was pretty damn stupid! The USN looked ahead, They did? And what crystal ball were they using? In 1945 the USN was looking no further ahead than the invasion of Japan, IMO. Not true by a long shot, as far as I can tell. figured they needed more destructive guns. The USAF insisted their .50" was adequate. A war proved the USAF wrong and the USN right. And all of those F9F Mig kills happened when...? What's the lethality of a 20mm firing pass compared to a .50 firing pass? What did the next generation of USAF fighters appear armed with? By this argument, roughly 5% of the US MiG kills in 1972 were scored by guns... suggesting that, far from being the crucial weapon often claimed, the gun was a relatively marginal weapon by then. It's your strawman, not mine. No, it is not. The .50 is an excellent weapon for strafing, according to you, making up in volume of fire for its lack of round-for-round lethality. So, why not a battery of .50s instead of the GAU-8? Why is the GAU-8 so much better for strafing than a battery of .50" guns? By your argument, the explosive HEI shells and the penetration of the AP rounds should be oughtweighed by the sheer volume of fire from a equal-weight battery of .50. There were no GAU-8s available in WWII. Period. We're now talking about arming the A-10 in the early 1970s, where there were both GAU-8s and M3 Brownings (and many other options beside) The threat was different in 1945 than it was in 1975 (if you had not noticed). Period. You understand now? Yes. When was the A-10 designed? When did strafing change so radically? The A-10 was designed for CAS/BAI. For tank-killing its primary weapon is the Maverick missile, for killing APCs/IFVs it uses guns and cluster bombs. Its 30mm was a armored vehicle killer. Period. Including tanks. Tanks that could be caught from behind without undue exposure of the aircraft. I submit that this is a fairly restricted target set. Period. It is only reasonable that it would have used its PGM's first against harder targets (duh!). Not "duh" at all, given the number of armchair commentators who insist that the GAU-8 is some sort of ultimate weapon (rather than a rather good airborne 30mm cannon) and that it is the A-10's "primary weapon". One of the problems the A-10 has acquired is excessive expectation: there is a significant fanbase that is convinced that the GAU-8 will defeat modern MBTs in the frontal arc, and base their thinking accordingly. Secondary armament is by its nature secondary. Show me where the .50 overcame its theoretical disadvantages to prove itself superior to the 20mm. Unlike you, I don't claim one was superior to the other. So, when was the last time anyone armed an aircraft with a battery of ..50 machineguns? I have repeatedly said that they were both effective, and nonone can draw any clear claim to superiority in the CAS/BAI role *during WWII* for either. Is that really that hard to comprehend? No, even though I disagree. The 20mm was more effective when analysed, but both batteries were pretty horrible for the recipients. The Lee-Enfield wasn't as effective as the M1 Garand, but it still worked well enough to serve out the war even though a .280 semi-auto would have been better (and a short-cased assault rifle even better yet). We didn't get an automatic rifle until after Korea (and I was still using the same rifle when I signed up in 1989). Doesn't mean the Lee-Enfield was bad - just that some other possibilities would have been better. Okay, I know you can't. Where was the last time anyone built a frontline fighter armed with .50" guns? _Everyone_ abandoned the calibre for fixed-wing jets in the 1950s (still valued for rotary-wing, but that's life) Are you going into serial production of scarecrows? The way you tote out these strawmen... No, I'm just curious. If the .50 was effective, why was it, the huge infrastructure for its production and its support, and all the trained crew to maintain it abandoned? Why change unless the 20mm was better? How many firing runs can you make? "One pass, haul ass" is a mantra for a very good reason. Not during WWII, apparently. Going "Winchester", or bingo on fuel, were the primary reasons for leaving the area. In other words, 'expendables' are key - fuel and ammunition. And guess what - weight spent on ammunition is weight not available for fuel. It's also not available for more bombs or rockets, which are the primary CAS/BAI weapons. Yep. Because going back for multiple passes against well-defended targets was a great way to lose pilots and aircraft. Oh, so now it is not general CAS/BAI we were discussing, as the thread started out, but attacking "well-defended targets" (not many CAS targets of the day met that criteria in regards to air defense). CAS targets tend to shoot back, with increasing effectiveness after the first attack. But hey, since you keep toting out the A-10 in this WWII based debate, why not give the groundpounders a few Stingers as well... That _would_ rule out most A/G guns use. Yes. The P-51B had huge trouble with its .50" guns at first - was that a problem with the M2 Browning, or the installation in the P-51B? Again, are you claiming that the 20mm cannon of the day were as relaiable as the M2's? Those in US service during WWII sure did not seem to be... The US had some self-inflicted problems in that regard: the UK was a lot happier with its guns. (Tony Williams, predictably for a historian of the issue, has chronicled the matter and offered a history) How many hits were scored at six hundred yards? How many kills were confirmed when fire was opened at that range? And just how freakin' close do you think the average strafe was conducted at? Far enough out for aircraft to routinely run out of ammo, apparently, meaning some _long_ open-fire ranges. Given issues of gun harmonisation, 800 yards would be a long open-fire range. We are talking CAS/BAI here; or do you think they all came back with telegraph wires and fir boughs in their cowlings? That's the problem of using guns for CAS/BAI: how to pull out in time without flying through own ricochets, or terrain, or ground fire, while still getting close enough to be effective. Quite possibly. No possible about it, unless you have managed to contravene the laws of aerodynamics and drag. Trouble is, the 20mm shells have explosive fillers, the .50 rounds do not. This makes quite a difference in that range band where .50s aren't effective but 20mm are still exploding. On the other hand, explosive shells are more lethal and less velocity-dependent than ball rounds. For gosh sakes, the amount of explosive in the 20mm of the day, not to mention its relative low pwer, did not make them the battlefield clearing agent that you seem to find they were. It made them significantly more lethal than a streamlined and ballistically-shaped 20mm ball would have been. (Otherwise, why bother with 20mm HE?) One has to wonder how many of those rounds buried themselves in the dirt before "burping" when used in the CAS/BAI role... Not enough to argue against the calibre, from the evidence. State your assumptions and we'll explore. ISTR the Tempest carried enough rounds for about sixteen seconds of fire, the P-47 some thirty-two seconds of fire. How many Tempests came home with dry guns per-sortie? How many Thunderbolts? How many Thunderbolts needed multiple passes on a target to kill it, compared to how many Tempests? If your fire is rapidly lethal, you need fewer rounds. Those atomic 20mm rounds of yours again? Yep. As confirmed by US procurement policy. Why transition? If the .50 is so good, why waste time and effort changing armament? Hey, you are the guy who claimed the F8F was 20mm armed (or was that keith?), Bulk of early production was, before the war ended and the changed version ended up an export version. If the war had ended in 1942, the Typhoon 1A might have defined British fighter armament as 12 x .303". and that the USN was heel-fired bent on changing to the 20 mm before the war was over, that no aircraft entered into production after 44 with the MG's, etc., right? Bearcat did (but switched to 20mm ASAP), Helldiver certainly didn't. I'm talking about new designs, you're talking about different letters of existing platforms (such as B-17F to B-17G) With different armament. You say the USN found the .50 cal was deficient--I have shown that it was quite possible to rectify that if they felt it as keenly as you claim, but they didn't. If there wasn't a problem, why change? In 1940, we'd lost most of our heavy weapons in France, and had to choose between keeping the 2pdr AT gun in production (adequate for today, clearly soon to be outclassed) or retooling for the 6pdr gun (a much better weapon - but what do we fight with in the meantime?) That we stuck with the 2pdr proves neither that it was inadequate for the existing threat, nor that the 6pdr was not superior. Source for that? (Nightfighters weren't a high priority then) The F4F-2N was a new build night fighter, completed by strapping a radar under the wing of an otherwise standard -2 series Corsair, and IIRC rearranging the MG's a bit. So it was a rebuilt airframe with some new systems (existing aircraft with a new radar added) rather than built-for-purpose.. Why did they want to, if the .50" was so good? Because they did decide to change to the 20mm--but they never really apparently found the difference between the two weapons that great a difference, as they were also quite happy to continue receiving and operating the MG armed aircraft until and after the war was over. You can have "not enough" M-16 rifles, or you can have "not enough" M-16s and "enough" M-14s. Reality isn't simple. Uhmmmm... yes No, you continue to ignore the change in threat and role. We're talking BAI against soft targets - if 20mm was inferior to 40mm, what does that say about 12.7mm vice 20mm? It's a very poor choice for use against targets under canopy, because it will tumble early. An overspun ball round is the requirement - don't know if anyone fielded such. The 7.62 does not tumble all that quickly, and then again, so what? You were going after an area target you could not see... a tumbling 7.62 would be quite nasty to the crunchie on the receiving end. But pretty useless against a truck, since it hits sideways, and trucks are the smallest targets likely to give you targets through canopy. You don't see a serious change both in German armour, and in their reaction to air attack, between 1942 and 1944? While fighters did kill German armor, with both MG's and cannon, during the latter part of the war, the rocket was the preffered round ISTR. OTOH, German horses, trucks, troops, and locomotives were pretty much the same throughout... Tanks were very hard to kill with any air-launched weapons. Rockets or bombs would kill with hits, but misses were survivable (whereas softer targets were killed by near-misses). Guns were unreliable in most sub-37mm calibres against tanks. (Trouble is, kill the tanker trucks and ammo wagons and the tank becomes useless very soon anyway). Yes, it is. Why did they go for a new calibre and new weapon unless they found it necessary to do so? Why not just keep buying .50"-armed Sabres if they're so successful? More straw... different war, different threat T-34s changed radically between WW2 and Korea? (Trouble is, using T-34s as the threat gets you into German 20mm and 30mm gun development, much-copied in the West; or Soviet 20mm, 23mm and 37mm guns with MG calibres largely relegated to flexible mounts) ....you need to study the concept of an evolving threat scenario, IMO. Kevin, that's what I get paid for. Have I told _you_ to instruct a maternal grandparent in the art of extracting ovine nutrition from its protective casing by the application of a local pressure reduction? -- When you have to kill a man, it costs nothing to be polite. W S Churchill Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk
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#59
August 20th 03, 12:06 AM
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In article , Paul J. Adam
writes How many 20mm shots were taken? The Navy's jets were relatively few in number and lacking in performance, but how many firing opportunities did they turn into confirmed kills compared to Sabres? Not forgetting the Sea Fury got a few Migs with the 20mm, certainly a situation helped by having a very destructive round, given they were right on the limit anyway. -- John
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#60
August 20th 03, 08:09 AM
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"Paul J. Adam" wrote in message ...
In message , Kevin Brooks writes Gentlemen, an entertaining debate but I have the feeling that not a lot more progress is going to be made. I would sum it up as follows: 1. The .50 M2 was one of the classic aircraft guns, and remained adequate to meet the demands upon it throughout WW2. 2. Cannon benefitted from the HE/I content of their shells, which magnified their effectiveness. A good 20mm cannon (MG 151/20, British Hispano) was more efficient than any HMG could be, in terms of destructiveness achieved for the installed armament weight. 3. The USA made a horlicks of manufacturing the Hispano, leading to serious unreliability, and this must have influenced their decision to stick with the .50 for as long as they did. Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk Military gun and ammunition discussion forum: http://forums.delphiforums.com/autogun/messages/
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