to late beating head on wall ah ah ah! from a book on guns in war war 2 listed in order of belived efectivness and best figerd out by rounds per sec musvelsity and he efects.
That is the most jumbled and muddled table I have ever seen! It is not apparent what units the table is in and what it is relative to with its percentages. As I posted before, there are only two ways of measuring the destructive force of a gun: Firing Power and Weight of Fire. Your table shows "firepower per weight." If you want to evaluate the quality of guns, look up "Gun Quality." Gun Quality is a measure of various aspects of a gun's performance divided by its weight. http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-pe.html is good site that states the following: The quality factor Q is a standard that Russian designers have been using to evaluate and compare guns. Basically, it is a power-to-weight ratio: The kinetic energy at the muzzle (which is one half the projectile weight multiplied with the square of the muzzle velocity) multiplied by the rate of fire in rounds per second, and divided by the weight of the gun. Essentially, this says how much power a gun produces for a given weight, and is similar to the horsepower-per-weight figure for engines. This Q value is a measure of the efficiency of a gun, not of its firepower: A light gun with a modest ballistic performance will have a better Q value than a powerful, but too heavy gun. Evidently it contains no information about reliability, accuracy, range, ammunition performance, or manufacturing cost. Nevertheless it is a sensible way to compare guns. (The higher the Q Factor the better.) The Russian UBS (on many planes on FH) has a Quality of 10.3. The Russian UBK, although not seen in Warbirds has a Quality of 13.5 The Browning M2 has a Quality of 7.7. All are 12mm guns, and I may note that the Russians made some very fine guns. My hats off to them, because I would love to have 4xUBS 12mm on my Ki-61-Ib. For 20mm the Gun Qualities are as follows: Hispano Mk. 2- 10.1 Hispano Mk. 5- 13.7 MG 151/20- 7.9 Russian B-20- 14.6 30mm... Mk. 108- 7.3 Therefore, caliber of the gun has little to do with its energy output/mass of gun rating. Higher caliber guns are more efficient at mass output/mass of gun, but that is what cannon do-hit the target with a heavy round for maximum explosive power. Again, 12mm are more efficient at Firing Energy rather than Weight of Fire, as seen by the data. Finally, there is the constant fact that 12mm are more accurate, have a higher rate of fire, have a flat trajectory, etc.
By the way Gryphn, that chart is off the same website I get my data. It is a great website, but it seems that some of the numbers did not copy correctly-the 262 should have 12.5 kg/second of weight of fire and not 2.5, I can see the "1" separated a little bit there.
really dint want to repost this its in must read on plane guns post.... this is auters explaination of chart
NOw you guys are just being ridiculous, Now your measuring rounds by effectiveness just by kenetic energy! And If thats the way you want to do it, I offer this example as a football player....You get a tight end running his heart out sprinting down the feild and trys to blow through this un-godly large peice of meat called bubba....He hits but then is just greeted into the ground after moving bubba no where. Were loosing the game, so we say"bubba, your gunna get the ball, and you gunna take it to the inzone" Bubba gets the ball and runs at an amazing 5mph! Everyone is stunned, but when lil ol linebacker star player joe gets in his way, he better be prepared because an object in motion stays in motion. For those of you that cant read percentages heres a new chart. 1x MK 108 - 87 rpg - 111 kg - 5030 kW firepower - firepower per weight: 45,31 kW/kg 1x MK 103 - 75 rpg - 210 kg - 4080 kW firepower - firepower per weight: 19,43 kW/kg 2x MG 151/20 - 207 rpg - 172 kg - 2540 kW firepower - firepower per weight: 14,75 kW/kg 2x Hispano V - 212 rpg - 188 kg - 2470 kW firepower - firepower per weight: 13,13 kW/kg 2x Hispano II - 206 rpg - 201 kg - 2120 kW firepower - firepower per weight: 10,56 kW/kg 3x MG-FF - 149 rpg - 235 kg - 2340 kW firepower - firepower per weight: 9,95 kW/kg 5x MG 151 - 239 rpg - 428 kg - 2190 kW firepower - firepower per weight: 5,13 kW/kg 10x MG 131 - 311 rpg - 413 kg - 2110 kW firepower - firepower per weight: 5,1 kW/kg 8x ,50 Browning M2 - 250 rpg - 452 kg - 2270 kW firepower - firepower per weight: 5,02 kW/kg 25x Browning ,303 - 399 rpg - 549 kg - 2190 kW firepower - firepower per weight: 3,99 kW/kg Also, the reason 20mm does so much better is that it is an EXPLODING CANNON ROUND and even though the explosion may not be that of a hvar, it non the less explodes AFTER making its larger entrance hole. The only way you are all defending the 12mm anymore is by saying "its more practical and easier to massproduce and yada yoda yina"
LOL! Watch "Varsity Blues" to find out, bubba is stated as "Billy Bob". "Come on guys! we are gunna do that stupid play where I run down the field and act like im lost again are we!?" "Guys, just give billy bob the ball...." -then the best part of movie- Tweeter drank beer because.....well, tweeter drinks beers....
Punch for the Fighter. In 1934 when the race began to develop fighters, the usual armament was two slow-firing (about 750 rounds per minute)rifle-caliber machine guns. Obviously their weight of fire would be insufficient to knock down the sort of bombers to be expected at the end of the decade, and in each of the major nations work began on heavier armaments for fighters. By 1939 fighters were in service with three basic types of guns: the fast-firing rifle-caliber machine gun, the slower firing heavy machine gun, and the shell firing cannon. At the outbreak of the Second World War all operational fighter aircraft carried rifle-caliber machine guns as all or part of their armament: the American browning .300 inch (7.62 mm) or the similar licence-produced British .303 (7.7 mm), the french MAC 7.5-mm, the German Rheinmetall Borsig MG 17 of 7.9 mm, the Italian breda SAFAT of 7.7 mm, the Polish Wzor of 7.7 mm, the Japanese Type 89 of 7.7 mm and the Russian ShKAS of 7.62 mm. Of these the ShKAS (Shpitalny Komaritsky Aviatsionny Skorostrelnu ? fast-firing aircraft gun) was, as has been mentioned, the best all-rounder; it had a rate of fire of 1,800 rounds per minute with a muzzle velocity of over 2,700 feet per second,all for a weight of 22 pounds. Prior to the war three nations had put into service fighters equipped with .5-inch (12.7mm) heavy machine guns; the U.S.A. with the .5 Browning, italy with the 12.7-mm Breda SAFAT and Russia with the 12.7-mm UBS. Of these the Russian weapon was again the best. The UBS (Universalny Berezina Skorostreny-Berezina universal fast-firing gun) had a rate of fire of 900 rounds per minute with a muzzle velocity of over 2,800 feet per second, for a weight of just over 47 pounds. Finally ther were the shell-firing cannon, of 20-mm caliber in each case(the arbitrary division between a machine gun and a cannon is that the latter has a caliber of 15mm or greater). At the beginning of the war thier were three types in service: the German Oerlikon, the French Hispano Suiza and the Russian ShVAK. Later the Oerlikon was manufactured under licence in Japan, and the Hispano was produced in Britain and , subsequently, in the U.S.A. With a weight of only 60 pounds the Oerlikon MG FF was the lightest of the cannon, while the 7.7-ounce round it fired was the heaviest of the three. On the other hand it?s rate of fire of only 350 rounds per minute and it?s low muzzle velocity of 1,950 feet per second meant that the german weapon had the lowest performance in these respects. The Hispano Suiza cannon of the early war period was the heaviest of the weapons at 109 pounds; it fired 4.4-ounce rounds at a rate of 700 per minute and a muzzle velocity of 2,820 feet per second, which meant that this weapon delivered a weight of fire about twice as great as that of the Oerlikon. The Russian ShVAK (Shpitalny Vladimirov Aviatsionnaya Krupno Kaliberaya ? large caliber aircraft gun) was different again, with a weight of 92 pounds and firing light 3.5-ounce rounds at a rate of 800 per minute with a muzzle velocity of 2,820 feet per second. The Oerlikon and the early Hispano Suiza cannon were fed from drum magazines with a capacity of only 60 rounds; the ShVAK was belt fed. During the first year of the war the trend was for aircraft to carry self-sealing tanks and armour protection for the crew positions, with the result that the effectiveness of fighters armed only with rifle-caliber machine guns was greatly reduced. The Royal Air Force had decided before the war that the Hispano Suiza was the best available cannon for use against armoured aircraft, as indeed it was. With it?s heavy projectile and very high muzzle velocity, the French cannon had a penetrative power about 50% greater than the ShVAK and double that of the Oerlikon. During the summer of 1940 there was a struggle to get the Hispano operational in the Spitfires and Hurricanes. But the Hispano had originally been designed for mounting along the top of the engine of the fighter, so that the latters weight could absorb the recoil forces; it did not take kindly to being pushed into less-rigid mountings out in the wings, which was the only place where there was room for it on the British single-engined fighters. The result was that the early career of the Hispano in the Royal Air Force was a sad tale of frequent stoppages and failures, as the cannon tried to shake apart itself and its feed system during firing. When in the spring of 1941 the problems of the Hispano were finally sorted out, the Royal Air Force possessed a very reliable and hard-hitting weapon which was to serve it well for the remainder of the war. In Germany the limitation of the Oerlikon were well appreciated before the war, but the wepaon had to serve until the more effective Mauser MG 151/20 was ready for service. The Mauser 20-mm cannon had a rate of fire of 750 rounds per minute and a muzzle velocity of 2,500 feet per second. Like the Russian ShVAK it fired a 3.5-ounce shell, and it was broadly comparable in terms of weight and because it too used belt feeding. The Mauser weighed a bit less and fired a bit faster than the Hispano, but it?s penetrative ability was considerably less. Meanwhile, far away in the U.S.A., there had been a progressive up-gunning of the rather feebly armed fighters which had been in service in that country?s air force at the beginning of the war. The armament fitted to new fighters moved up through various combinations of .3 and .5-inch machine guns and 20-mm and even 37-mm cannon, until by the early part of 1942 it began to settle at four, six, and eight .5-inch Browning heavy machine guns. Although the .5-ince Browning lacked the penetrative power of the 20-mm cannon the U.S. Army Ordinace department believed, rightly as it turned out, that this weapon would be perfectly adequate against the enemy aircraft likely encountered during the second world war. The Germans never armoured their aircraft to withstand .5-inch rounds, and the Japanese certainly did not. But incase their hunce was wrong the Americans played it both ways and put the Hispano cannon into limited production; known as the M-2, the licence-built weapon fitted into a small proportion of their fighters. By the middle of the war all of the combatant nations had begun or completed the replacement of the rifle-caliber weapons in their fighters with cannon or heavy machine guns. The Japanese produced a near copy of the .5 Browning as the 12.7mm type 1 machine gun, the German Rheinmetall Borsig company produced the 13-mm MG 131 which fired a lighter round at a lower muzzle velocity then the Browning, though with a slightly higher rate of fire; the Russians gradually replaced the rifle-caliber ShKAS gun with the UBS; and the Royal Air Force belatedly replaced the .303-inch machine gun in its Spitfires with .5-inch brownings, when it was finally able to get hold of these precious weapons. Against fighters or medium bombers carrying normal amounts of armour the fire power of the .5 inch heavy machine gun was adequate and that of the 20-mm cannon was ample. The trouble was, as the Germans and the Japanese began to descover from the latter half of 1942, that these weapons simply weren't powerful enough against the tough american B-17 and B-24 heavy bombers. For example, the Focke-wulf Fw 190-A3 carried an armament of two Oerlikon Mg FF and two Mauser MG 151/20 20-mm cannon, and two rifle-caliber machine guns; during a three second burst these guns loosed off 130 rounds each of 20mm and 7.9 mm ammunition. On the average, twenty hits of 20mm were required to bring down one of the American heavy bombers (it must be stressed that this was the average figure; some bombers were shot down with less hits,some returned with more.) unless they scored a lucky hit on the pilot or some other vital part, the rifle-caliber weapons were of little value in such an engagement. During the analysis of air-to-air combat films, Luftwaffe armament experts found that the average fighter pilot was hitting a bomber with only about 2% of the aimed rounds that were fired. Thus, to obtain the twenty hits required to shoot down the heavy bomber, one thousand rounds of 20-mm ammunition had to be aimed at it; this represented 23 seconds? firing time for the fw 190A-3, an impossibly long time if the bomber was still in formation and the fighter pilot was on the receiving end of heavy defensive fire. It was found that the majority of the heavy bombers shot down by fighters fell either to the aces, who were beating the odds and getting far more than 2% of their rounds on the target, or else the bombers had first been damaged during previous fighter attacks or from flak and forced out of formation, and were then finished off in long firing passes pressed home to short range. Dr Samuel Johnson once assured us that when a man knows he is to be hanged in a fortnight, it concentrates his mind beautifully. By the Autumn of 1942 the Luftwaffe High Command knew that unless something was done soon they faced the prospect of having to meet large-scale daylight attacks on the German homeland, without adequately armed fighters. And the thought of that concentrated their minds beautiffuly. Fortunately for the Luftwaffe, at this time the Rheinmetall borsig company had 2 30-mm heavy cannon in an advanced state of development and one of these, the Mk 108 was chosen as the standard bomber-destroyer weapon. The Mk 108 had a high rate of fire of 660 rounds per minute, though its muzzle velocity was only 1,750 feet per second. Its 11-ounce incendiary or high explosive shell had an effect on aircraft structures which was truly devastating: against fighters or medium bombers a single hit was almost invariably sufficient to cause their destruction; against a four engined heavy bomber, three or four hits were usually enough. During 1943 the MK 108 went into action fitted the the messerscmitt Bf 109, which carried one, and the messerscmitt Bf 110 and the focke-wulf Fw 190 each of which carried two. When the Me262 jet fighter entered service in 1944 it carried the unprecedentedly heavy armament of four Mk108 guns; complete with the mountings and 360 rounds of ammunition, this battery weighed more then 1,100 pounds and could loose off a projectile weight of 96 pounds during a 3 second burst. This was far away the heaviest weight of fire possible for an operational gun-equipped fighter during the Second World War and when it struck home the effect on the victim was usually catastrophic. For all its destructive power, however, the Mk108 was not the complete answer to the Luftwaffe?s problem. It was a low velocity weapon; to cover 1,000 yards its shell took over two and a half seconds, and they dropped nearly 100 feet before they got there. Clearly this was no weapon for long-range firing against moving targets, and to use it the german pilots still had to press home their attacks to well inside the range of the bombers? defensive fire. In an attempt to knock the bombers out of formation at longer ranges, the Germans introduced a modified version of the 50-mm high velocity gun fitted to some of their tanks; with automatic loading and a new recoil system and barrel, this weapon became the BK 5 which was fitted into the Messerscmitt Me 410. The BK 5 fired shells weighing 3.5 pounds, large enough to knock down a heavy bomber with a single hit; leaving the muzzle with a velocity of 3,000 feet per second, they took just over a second to cover 1,000 yards and the gravity drop was only 24 feet. The rate of fire of only 45 rounds per minute(3 in 4 seconds) was inordinately slow, but it was felt that the weapons high velocity and destructive power would more then make up for this. The combination of the Me 410 and the BK 5 seemed to provide an ideal solution to the problem of stemming the American heavy bombers. But in war nothing stands still. By the time the new bomber destroyer was ready for action, in the spring of 1944, the American escort fighters were operating over Germany in such numbers that the slow deliberate attacks from behind the bomber formations were quite out of the question. To replace the Mk 108 as the standard German heavy cannon, the Mauser company came up with its tour de force, the magnificent MG 213. Intially produced with a caliber of 20mm, the MG 213 was later to have been built in a 30-mm version as well. The 7.4-ounce shell of the 20-mm were twice as heavy as the noraml projectile for this caliber, and the Mg 213 spewed them out at a muzzle velocity of3,300 feet per second and a rat of 1,200 per minute. The reason for this superb performance was that the weapon was fitted with a unique revolving chamber which served as both breech and part of the feed mechanism. Just to late to see action during the Second World War, the Mg 213 represented the zenith of aircraft gun design in 1945 and dominated it for more then a decade afterwards. After the war everybody copied its clever feed system which was used in the American M-39, the British Aden, the French DEFA and the Russian NR 30 cannons. In an effort to produce a really effective bomber-destroyer, the Japanese fitted 30-mm, 37-mm and even 40-mm cannon to their fighters. The 30-mm Ho 105 was an effective weapon with a muzzle velocity somewhat higher than that of the German MK 108, though its rate of fire was lower. The 37-mm Ho 23 was greatly inferior, with a rat of fire of only 120 rounds per minute. The 40-mm Ho 301 fired an unuasual type of round without a cartridge; the propellant was housed in a compartment at the rear of the projectile, and when it was fired the expanding gases impinged on the breechthrough hole cut in the rear of the round. This method had the advantage that there was no cartridge case to extract from the breech before the next round was rammed home; as a result the cannon had a rate of fire of 450 rounds per minute, which was remarkably high for a weapon of this caliber. The great disadvantage was that the weapon had a muzzle velocity of only 760 feet per second, by far the lowest of any air-to-air gun used during the conflict, and because of this its effective range was limited to about 150 yards. During the war the Japanese heavy cannon saw only limited use, and they did not make any noticeable impression in combat before it ended. please excuse any mistakes, was up rather late when i typed it. Information was gathered from the book Fighter Combat. combat developement in World War Two By Alfred Price ISBN 0-85368-926-1 bullet
Hmm, seems clear to me, the more punch the better....That ROF and "massproduction" does not insure victory. Id still like to think of the glorious p51 coming in and shooting down a 4 engined bomber with only 4-even 6 50's.....haha, good times.....
ah but some weres in here is a post of ki47 suposidly downing 4 hvy bombers and p38 i sorite with 12mms.
Lucky coincidences such as pk's already dmged planes and extra-ordinary things like that........oh, and ki47?
Allsop, you are missing the point. The fine information provided by bizerk shows how Air Forces around the world tried to improve the performance of their 20mm and 30mm by making the velocity higher. It can be said that they were attempting to make their 20 and 30mm's into scaled-up 12mm's. This shows how the Luftwaffe found their MG 151/20's and Mk. 108's deficient. America never found its 12mm deficient against German fighters or even their bombers and nothing would be deficient in bringing down the majority of Japanese aircraft. I can say this because they did not upgrade their aircraft armament like England and Germany did.
But you are missing mine For the .50s to be effective they must be used in 3 ways. 1. High amounts of rounds hitting the target 2. High ROF 3. High FPS otherwise the shell is only effective because of its numbers. So you must be able to have... 1. More guns 2. More rounds 3.Higher ROF I luftwaffe pilot needs only 1. a few good mg/151's 2. Fewer rounds 3. Only a snap shot worth of rounds. So all and all Id say the 20mm is better. Besides, and Ill say it again, your changing the arguement into a 'reliability" factor or something of the sorts, when the true arguement is what round does more damage. And I think everyone agrees that even when deployed in bursts of 3 or 6 a 50 cant come close to a good 151 20mm round.
It was you who brought up the Firepower vs. Weight of whatever that was. Yes, a plane needs fewer 20mm guns and less ammunition. However, the guns themselves and each individual round is heavier. A single MG 151/20 gun has a mass of 42 kg. Plus 5-20 kg of reinforcement for recoil. A single Browning M2 has a mass of 28 kg._____ Ratio- (1.67-2.21):1 A single MG 151/20 round has a mass of .485 lbs. A single 12.7x99mm Browning M2 round has a mass of .255 lbs._____ Ratio- 1.9:1 So for every cannon a plane can carry, it can carry about twice as many in 12mm guns. A plane with 12mm can carry at least twice the ammo of a plane with 20mm. However, once ammo is consumed, a plane with 12mm has the advantage as it has less "dead weight" in the plane.
There you are incorect, See, once any of these american planes have burned up amuntion, they are left with extra guns in the wings that are just DEAD WEIGHT. As oposed to having 20mm guns with no ammo. Plus, figure ammo is comparitivly unfair to win your arguement as most U.S. planes have say 1800-4000 rounds? something like that. While say a fw190 will have...maybe 1800 if a full version with 900xmg rounds.....So still, the 50 cal using planes would be heavier AND less effective in damage. And this entire arguement was about damage....I think its unanamous, the 20mm wins.
>So for every cannon a plane can carry, it can carry about twice as many in 12mm guns. Still, to get firepower equivalent to 2 x 20 mm MG151/20, you need 9 x 12.7 mm Browning M2 guns. 2 x 42 kg = 84 kg 9 x 28 kg = 252 kg Advantage 3:1 for cannon >A plane with 12mm can carry at least twice the ammo of a plane with 20mm Cartridge mass including belting: 1 x 12.7 x 99 mm API: 122 g for 21.8 kJ => 179 kJ/kg 1 x 20 x 82 mm (average): 192 g for 106 kJ => 552 kJ/kg Advantage 3.1:1 for cannon Thanks masked helper
We were talking about weight and then you move back to firepower over weight. The bigger a gun gets, the heavier it becomes, yet you are trying to prove how 20mm are lighter when you are not considering the heavy reinforcement necessary to put cannon on an aircraft and the greater aerodynamic drag of both a 20mm barrel and the lumps on the wings (look at a Spitfire with 20mm cannon). Must I restate the valid points I have already made? The Luftwaffe was disappointed with the performance of its 20 and 30mm. America never modified its M2 Browning. Getting back on track with the initial theme of this thread, the only advantage 20mm has in its ability to destroy aircraft is that it does more damage per hit.
Lets see, the drag on 2x20mm barrels, even 4x20mm barrels is not more suggnificant than 6x50 or 8x50caliber in the wings, as the farther out in the wings the more loading they will make by leverage on the base of the wing, as far as internal weight. Lets look at the killing power of a 190a4 or a6 lite versus that of a ki43.....The 190 no doubt does ALOT more damage....now for a 50 cal plane to have near the same rusults you would need a p47 or something like that, with more guns, more ammo, there for more weight, and more drag. Maybe gun for gun the 50cal MIGHT be more effiecient in weight and drag and all that jazz, but as far as the real world and doing damage, the 20mm is a far sounder option. You could esentially have a 190 lite and do more damage AND have less weight and less drag, using far less rounds and far less guns than any american plane, and do a tremendous amount more damage and still be lighter........so instead of argueing gun for gun, atleast try to defend needing 6 or 8 of them compared to 2 of a type, or even just 1 as a nose or cowl cannon with 7mm/13mm mg's....that would still be lighter and offer less drag "probably a better center of gravity, and still do more damage. The 50cal is bust. The true advantage of 20mm is damage per unit/per unit. I.E. 1x20mm cannon is equal to atleast 3-6 12mm shells and to do a true damage you would need 6 of them as compared to 1. So not only do you get more effiecensy with 1x20mm than needing to hit ATLEAST 3-6 12mm, and you only need 1/6 or 1/8 of the guns to do the same damage. Id say that leaves the 12mm with the only advantage being ROF and flight path....balistics is all it really offers.
In every 12mm on a fighter I have seen, the entire gun, including the barrel was contained in the wing. A Hispano 20mm on the other hand has a bulge on the wing surface with a large barrel protruding from the leading edge of the wing. The MG 151/20 on a 190 also has a barrel and a bulge. The Browning M2's on the P51, F4U, P47, F6F and P40e all have a little hole in the wing for the barrel to fit flush into the leading edge of the wing and no bulge on the wing at all. In fact, the only drag a 12mm makes is by its little hole in the leading edge and the holes for the casing release-found in all wing guns but abbreviated in 12mm because it is a smaller gun. This is a common misconception about aerodynamics. The only time leverage on a wing matters is when the plane is on the ground or landing-with the landing gear position factoring here. The rest of the time, the wing is the part that holds up the fuselage, not the other way around. Therefore, the kind of stress acting upon the wing root is a shear force, not a tensile force, because the wing wants to go up, and the weight of the fuselage wants to go down-two opposite directions-shear. Leverage would not factor in at all because it is a tensile force, not a shear force. Anyway, you are in agreement with me-20mm has a better shot-for-shot damage, 12mm has ballistics. Why can't we leave it at that? You like the 20mm because it does more damage with each hit and you don't mind needing to calculate the extra trajectory, I like the 12mm because it is easier to hit the target and with more hits. I don't mind the fact that 12mm does less damage with each hit, because let's face it, no bullet improves the structural integrity of its target. "All light beers are low in Carbs, why don't you choose on taste?"
