Again I'm in disagreement, both the British and German designers went to great lengths to protect their pilots, the British used equipment such as the radio and oxygen system in front of the armour to create spaced armour, it worked the same as the hollow wedges fitted to mantlet of the Leo2
Japanese Zero vs Spitfire vs FW 190 (6 Viewers)
- Thread starter Chiron
- Start date
Again I'm in disagreement, both the British and German designers went to great lengths to protect their pilots, the British used equipment such as the radio and oxygen system in front of the armour to create spaced armour, it worked the same as the hollow wedges fitted to mantlet of the Leo2
Hello Pat303,
I don't think spaced armour on Tanks is really for the same reason unless you are expecting to be attacked by shaped charges (Monroe Effect) such as from a PIAT or Bazooka or HESH rounds. Regardless of armour, the majority of an aircraft's structure is a soft target. Note that the Germans eventually equipped their cannons with thin case "Mine shells" which had no AP capability but carried more explosive.
The first question would be WHICH .50 caliber HMG was tested against the .303? If it was the British .50 cal, that was not a powerful gun. You do realize that the Spitfire eventually did substitute 2 x .50 BMG in the inboard cannon bays for the 4 x .303 in the outer wings.
There must be more to this test than what is described here. I can't imagine armour penetration from a single angle is the only deciding factor. If this is the .50 BMG, it has advantages in initial and retained velocity, about 4 times the bullet mass and even moving sideways is going to tear up some soft structure of an aircraft.
You also might want to note that German statistics on the number of hits to make a kill suggest that the end result of all this "hardening" didn't really make a difference.
- Ivan.
Ah, yes! You got me there, Ivan. Indeed it was. I should have put N1K1, but you know what I meant.
The A8K was to have a Nakajima Homare 21. Here is a picture of the J6K1 mock up, the type that the A8K was to be based on, with appropriate data:
日本の名機（陣風）
This is the instrument panel for the Jinpu:
CG 日本海軍 18試甲試作戦闘機「陣風」
The J6K was derived from the projected J3K (17-Shi Fighter) fitted with a two-stage supercharged Mitsubishi HA-43, originally Kawanishi wanted the Homare, but the navy ordered the Mitsi engine, but the HA-43 was troublesome in development and because Kawanishi was working on improving the N1K1 into the N1K2, the J3K quietly disappeared and was resurrected as the J6K with the supercharged Nakajima Homare 42.
Hm, not sure. Perhaps it was the first publicly released in-depth information on the type? Although the Aleutian Zero, an A6M2 Zero 21 had been analysed and test flown against US types, its recovery and subsequent tests were kept secret for some time after the fact.
I have a clue regarding the use of the Zero Mk 2 appelation, on the dataplates, of which I have seen of an A6M2 and '3, the second line down from the top stipulates the aircraft name. The A6M2 is as follows: "Reishiki Type No.1 Carrier-borne Fighter Plane , design 2" and I reckon that the A6M3 is likely to read "Reishiki Type No.2 Carrier-borne Fighter Plane, design 3" See below:
https://www.pacificwrecks.com/aircraft/a6m3/3018/dataplate/dataplate3018.jpg
In Japanese, the Zero was Reishiki Sento Ki, or Type Zero Fighter, shortened to Rei-sen - apparently the A6M designation was not frquently used by the Japanese and Zero-sen became the common use name for the type, which we know already.
Without getting into the specific armor panoplies of each major aircraft type, which were not, lets just say, always ideal, let alone the notion that .30 caliber bullets had equivalent armor penetration to .50 caliber (if this was really the conclusion of an RAF study, why did they start putting .50 cals on RAF fighters late in the war?), how many rounds of 20mm cannon shells do you think a given fighter aircraft can absorb without going down? Ten? Twenty? Thirty?
The armor only protects certain vital area. You put 5 or 10 cannon shells in the wing root or tail of most WW2 fighters and they are going to break apart. The same will happen with enough .50 cal or equivalent HMG, or even (at closer range) enough LMG bullets.
Nor is 5 or 10 or even 15mm of armor necessarily going to even stop a heavy caliber bullet, especially armor piercing bullets or shells.
Yes the armor helped, no it was no guarantee.
cherry blossom
Senior Airman
- 556
- Apr 23, 2007
On the subject of fitting the Kinsei to the A6M, the Kinsei 50 series was in production in 1941 and was fitted to the H6K5 flying boat, which was ordered into production in case the H8K was seriously delayed and delivered over 1941 and early in 1942 with production stopped once the H8K was seen to be a success. They were also used by the G3M3, the last G3Ms produced.
Using data from q‹ó‹@ƒGƒ"ƒWƒ"ˆê——E"ú–{ŒR (Goodwin and Starkings agrees but leave some numbers as question marks), for take off we have 1300 ps at 2600 rpm for the Kinsei 51 and 1130 ps at 2750 rpm for the Sakae 21. At 6200 metres, the Kinsei 51 gave 1100 ps at 2500 rpm while at 6000 metres the Sakae 21 gave 980 ps at 2700 rpm (both translated as military power). The Kinsei weighed 640 kg compared to 590 kg for the Sakae.
Thus a 1941 A6M8 would have lost the two 7.7 mm machine guns, increased in weight and probably in fuel consumption but benefited from an extra 120 ps at altitude. The Kinsei 60 series was first used in December 1942 for the Ki-46 III prototype. The variant powering the real A6M8 gave 1250 ps at 5800 metres and 2600 rpm (probably with an extra bearing to allow higher rpm but with an increase in weight to 675 kg). The A6M8's quoted max speed of 356 mph suggests that we would see about 341 mph with a Kinsei 50 series engine ignoring the slight difference in weight. However, the A6M8 was able to dive significantly faster than a 1941 Zero due to thicker skinning and carried a heavier armament.
Using data from q‹ó‹@ƒGƒ"ƒWƒ"ˆê——E"ú–{ŒR (Goodwin and Starkings agrees but leave some numbers as question marks), for take off we have 1300 ps at 2600 rpm for the Kinsei 51 and 1130 ps at 2750 rpm for the Sakae 21. At 6200 metres, the Kinsei 51 gave 1100 ps at 2500 rpm while at 6000 metres the Sakae 21 gave 980 ps at 2700 rpm (both translated as military power). The Kinsei weighed 640 kg compared to 590 kg for the Sakae.
Thus a 1941 A6M8 would have lost the two 7.7 mm machine guns, increased in weight and probably in fuel consumption but benefited from an extra 120 ps at altitude. The Kinsei 60 series was first used in December 1942 for the Ki-46 III prototype. The variant powering the real A6M8 gave 1250 ps at 5800 metres and 2600 rpm (probably with an extra bearing to allow higher rpm but with an increase in weight to 675 kg). The A6M8's quoted max speed of 356 mph suggests that we would see about 341 mph with a Kinsei 50 series engine ignoring the slight difference in weight. However, the A6M8 was able to dive significantly faster than a 1941 Zero due to thicker skinning and carried a heavier armament.
Shortround6
Lieutenant General
If you are shooting bare armor (armour with nothing in front of it) the .50 has a tremendous advantage over the rifle caliber machine guns. however what the British found with their tests was that the .50 cal bullets yawed/tipped more than the smaller caliber bullets after penetrating skin/light structure, especially if the impact angle was low. AP bullets that hit armor while going sideways don't penetrate very well.
We are also confusing things here with the British use of the .50 in the Spitfire. The British started fitting the .50 cal guns once they had gone to gyro gunsights, The .50s extra striking power was no longer balanced against the much greater hit probability of the four .303s. The Gyro gun sight raising the hit probability of the 20mm and .50 cal guns substantially
Most fighters were NOT going to stand up to very many 20mm hits (like 4-5) as shown by the Spitfire in the photos earlier in the thread. 3 hits and the plane never flew again, Note buckling of rear fuselage in photos although I don't know if it happened in flight or upon landing. Germans figured about 20 rounds of 20mm ammo to take out a B-17 on average. Chances of any single engine fighter surviving more hits than a B-17 are pretty slim.
Armour penetration depends an awful lot on "clean" hits and high angles of impact (near 90 degrees)
I would note that the British and Germans both used "spaced" armor on tanks long before shaped charges became common. The spaced armor again worked by causing the projectile to tip and not hit the main armor square and by sometimes causing the cap of capped projectiles to come loose before hitting the main armor.
This last "trick" was sometimes used on ships and a thin armour bulkhead or deck was referred to as a decapping bulkhead or deck in the path before the main armor was hit. There was some controversy on this and not all naval architects thought that was a better use of weight than one thick piece of armor.
The Hurricane had an excellent roll rate:
A Critical Analysis of the RAF Air Superiority Campaign in India, Burma and Malaya in 1941-45
Not to mention the .50-in trajectory being a far better match with the 20-mm throughout the effective range of the Gyro sight. Whereas with the relatively short-ranged capabilities of a regular sight the .303-in / 20-mm discrepancy wasn't much of an issue.
We've been over that before in great depth - no it didn't.
I'm going to leave the other (to me ridiculous) debate about LMG vs. HMG alone, this is the point I was making. I might put the threshold slightly higher depending on the fighter but that was the same point I was making - a short burst of 20mm cannon could knock out just about any fighter. Armor helped and it's also possible the fighter might survive but it's no guarantee.
fubar57
General
michael rauls
Tech Sergeant
- 1,679
- Jul 15, 2016
Some surprising info in that chart. Most notably the later model p38s outroll anything( save one model of the p40) if you really keep it moving. Not what I would have expected to see.
ThomasP
Chief Master Sergeant
The Air Ministry tests of .50 cal Browning vs .5" Vickers vs .303 cal MG (various makers) took place from 1932-1935.
At the time the .50 cal Browning had a MV of 2500 ft/sec max for the longer barreled version, and around 2350-2400 ft/sec for the aircraft version. ROF was in the 500-600 rpm range max. The .5" Vickers had a MV of 2500 ft/sec and a ROF of about 650 rpm in the aircraft variant. The .50 cal Browning had a heavier projectile.
The various .303 cal MGs tested had ROFs of from 900-1200 rpm.
Although the armour penetration of the .50 cal and .5" was a little higher than that of the .303 cal it was not considered a significant difference.
The Air Ministry concluded that for use against fighter aircraft (none of which had armour or SSFT at the time) the higher ROF and greater number of guns that could be carried were more important than the size of round. This was not considered ideal against larger aircraft (ie bombers) but was acceptable until the preferred 20 mm cannon became available.
Fans of the .50 cal Browning might like to know that ammunition with MVs of 2700-2900 ft/sec only began entering service in any significant volume in 1940.
At the time the .50 cal Browning had a MV of 2500 ft/sec max for the longer barreled version, and around 2350-2400 ft/sec for the aircraft version. ROF was in the 500-600 rpm range max. The .5" Vickers had a MV of 2500 ft/sec and a ROF of about 650 rpm in the aircraft variant. The .50 cal Browning had a heavier projectile.
The various .303 cal MGs tested had ROFs of from 900-1200 rpm.
Although the armour penetration of the .50 cal and .5" was a little higher than that of the .303 cal it was not considered a significant difference.
The Air Ministry concluded that for use against fighter aircraft (none of which had armour or SSFT at the time) the higher ROF and greater number of guns that could be carried were more important than the size of round. This was not considered ideal against larger aircraft (ie bombers) but was acceptable until the preferred 20 mm cannon became available.
Fans of the .50 cal Browning might like to know that ammunition with MVs of 2700-2900 ft/sec only began entering service in any significant volume in 1940.
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If the plane saves the pilots life, either by letting him land like the Spitfire did in my earlier post or by allowing him to get out before it burns it's done it's job, bothe the RAF and Luftwaffe fitted protection to all their planes before the commencement of the BoB after what they learnt over France. The total lack of protection the A6M gave it's pilot is a flawed idea.
The first question would be WHICH .50 caliber HMG was tested against the .303? If it was the British .50 cal, that was not a powerful gun. You do realize that the Spitfire eventually did substitute 2 x .50 BMG in the inboard cannon bays for the 4 x .303 in the outer wings.
There must be more to this test than what is described here. I can't imagine armour penetration from a single angle is the only deciding factor. If this is the .50 BMG, it has advantages in initial and retained velocity, about 4 times the bullet mass and even moving sideways is going to tear up some soft structure of an aircraft.
You also might want to note that German statistics on the number of hits to make a kill suggest that the end result of all this "hardening" didn't really make a difference.
- Ivan.[/QUOTE]
Watch from around 55 seconds, the bullet keyholes and deviates off target shooting through thin steel sheet, the same thing happened during the RAF testing, the bullets tumbled after entering the rear fuselage and hit the seat armour sideways giving no penetration advantage over the 303 guns.
There must be more to this test than what is described here. I can't imagine armour penetration from a single angle is the only deciding factor. If this is the .50 BMG, it has advantages in initial and retained velocity, about 4 times the bullet mass and even moving sideways is going to tear up some soft structure of an aircraft.
You also might want to note that German statistics on the number of hits to make a kill suggest that the end result of all this "hardening" didn't really make a difference.
- Ivan.[/QUOTE]
Watch from around 55 seconds, the bullet keyholes and deviates off target shooting through thin steel sheet, the same thing happened during the RAF testing, the bullets tumbled after entering the rear fuselage and hit the seat armour sideways giving no penetration advantage over the 303 guns.
Again, was that RAF test conducted with Browning or Vickers .50s? The different cartridges are apt to give different terminal ballistics. I don't know if the cartridge in the video was Browning M2 or not, but I did notice it went through 6 sheets of 18 gauge steel before it started to keyhole, which is a lot more than the 1 or 2 pieces of aluminum it would encounter in the aft fuselage of a WWII fighter before it hit the armor.
Our old weapons instructor in ROTC, Sergeant Garland, said the Browning .50 M2 was a stand out in its class due to a heavier projectile, higher muzzle velocity, and gain twist rifling which imparted a faster spin to the projectile, giving it more stability and greater effective range. He should know, as he was a .50 cal gunner in Korea. He said he could take out a NK 12.7 mm team before they could get close enough to use theirs. "The gooks learned to respect a 50."
Cheers,
Wes
The British tested both the Browning and Vickers .50, the reason the .50 BMG out ranged other guns was also the reason it tumbled, the sleek ballistic shape of the bullet made it base heavy causing it to be knocked off axis and tumble with minimal effort, the exact design feature of the Mk7 303 round and the reason for its effectiveness on men, furthermore, the British found that the bullets tumbled after entering the rear fuselage because of the oblique angle they impacted on, notice on the video that the bullet tumbled after only six sheets set at 90 degree's.
Shortround6
Lieutenant General
As Pat303 has said. to simulate the aircraft scenario put a sheet of metal (even aluminium) at about 10 degrees or less to the flight path of the bullet a number of feet from the armor.
As a side note, the Americans started getting the high velocity .50 cal ammo in 1940, how quickly it replace the low velocity ammo is subject to question in 1940/41. HUndreds of thousands of rounds of the low velocity ammo were sold to the British as surplus before lend lease and to get around other neutrality laws.
The British were placing orders for the low velocity ammo in 1940-41 and delivers took place when? Please note British .50 cal ammo (as opposed to .5in) was supplied by both a British company and one (Remington) or more ( surplus? American ammo through a loop hole before lendlease).
I don't know when or if the British ever changed their specifications on .50 cal ammo or simply took lend lease American ammo.
As a side note, the Americans started getting the high velocity .50 cal ammo in 1940, how quickly it replace the low velocity ammo is subject to question in 1940/41. HUndreds of thousands of rounds of the low velocity ammo were sold to the British as surplus before lend lease and to get around other neutrality laws.
The British were placing orders for the low velocity ammo in 1940-41 and delivers took place when? Please note British .50 cal ammo (as opposed to .5in) was supplied by both a British company and one (Remington) or more ( surplus? American ammo through a loop hole before lendlease).
I don't know when or if the British ever changed their specifications on .50 cal ammo or simply took lend lease American ammo.
