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Wasn't the 4 20mm and 4 303 an overload for some of the malta spits of the USS Wasp? I thought they weren't carrying any ammunition and 2 of the cannons were removed as soon as they landed. This was from a flight journal article so take with a liberal amount of salt....As far as I know it was the drag of the protruding cannon that made the difference. In 1940-41 when they started fitting cannon to RAF fighters, the 0.5cal wasnt a viable option, not reliable, low rate of fire and USA not in the war. The Spitfire could carry 4 cannon and 4 x 0.303 " there were mock ups with 6 x 20mm cannon
Thanks. Was wondering, yeah , seemed a tad ludicrous. I think there's a report somewhere on here that it (Spit V)was too unwieldy with 4 cannons. Will see if I can dig it up.four cannon OR two cannon and four .303s.
True but they were moving relatively small quantities. Keep in mind the shortest east to west distance across the United States is ~10% greater than the distance between Paris and Moscow. The US is huge. The economics and logistics of the US is far more complicated than it is for the UK or any other nation for that matter. It's far easier to ship something 20 miles or 200 miles from a factory to the front line than it is to ship something 1000 miles to a port then have it prepared for a long ocean voyage. Effectively the US had many weeks of extra delays built into any of their decisions.UK had to move all this around, Commonwealth small arms calibers and Lend Lease received from USA
38 S&W
9mm
455 Webley
45 Auto
303
30-06
8mm Mauser
50 Browning
50 Vickers
55 Boys
15mm BESA
The Spitfire needed more fuel not more guns.There was room for 4x 20mm + 4x .303 cal and this combination could have been fitted - you can see in the following diagram of the 'C' wing that there was room for the guns and ammo boxes. How bad the decrease in performance would be, and whether weight and/or dynamic stresses on the wing structure would have allowed it, I can not say.
View attachment 759997
You can have too much of a good thing.Mk.XII with 6 Hispano mock up, to test possible handling deficiencies
View attachment 759929
There were a number of schemes/proposals for planes with six 20mm Hispano's. (Meteor was supposed to have six) but they came to nothing.You can have too much of a good thing.
Yes, & test-pilot R. Beamont instigated the adaptation of the Spitfire cannon fairing to the Typhoon, did the RAF's cannon Mustangs get 'em?In service the 4x 20mm of the Hurricane Mk IIC lowered the Vmax by about 1.5-2 mph per 20mm ( total of about 6-8 mph). I have read that the Spitfire Mk VB/C & Mk IX had their Vmax reduced by about 2-3 mph per 20mm installed (total of about 4-6 mph for the 'B' wing and 8-12 mph for the 'C' and universal wing).
My only criticism would be the different points of impact between the wing and centrally mounted guns, one way to overcome it could be harmonizing them into a cone shaped POI maybe. My opinion, wing root mounted Hispano's like the 190's cannons zeroed to shoot parallel straight ahead would be my choice.The sweet spot for WW2 era aircraft seems to be 3-4 20mm cannons.
Perhaps the best all around compromise between weight of fire and all-up weight was probably the Yak-3P, or Fw 190 D-13, with 3 centrally mounted 20mm auto cannon.
I have no idea why he would?I do not recall ever reading where a P-38 pilot decided to shoot just his 20MM cannon because it was more effective, although most of the airplanes were equipped with separate machine gun and cannon firing buttons.
Yes, the the p-39 was famous for having .50 cal, .30 cal and 37MM, all of which were ballistically different enough to make hitting a target that was not dead nuts ahead and at close range something of a challenge. One pilot who flew P-39's said it was VERY important to only fire the 37MM when you had positive G's, not negative. The gun needed gravity to keep the shells being fed properly; to do otherwise risked a jam. You did not dive and open fire. You dove, then pulled up a bit as you fired the 37MM.Just about anything else was worse, sometimes way worse.
One pilot who flew P-39's said it was VERY important to only fire the 37MM when you had positive G's, not negative.
Supposedly they used a "Christmas Tree" gunsight with different marks for each type of gun.No Idea how they synchronized the gunsight, gun housing and range input
Perhaps the P-38 would have been better off by deleting the four .50 cal's, and adding one or two more 20mm cannons instead. The installed weight would be similar, but increased lethalityI think the P-38 would have been better off with one or two more .50 cal in the nose rather than the 20MM cannon. A 15MM cannon like the BF-109F had might have been a good compromise, and hence the value of up-scaling the .50 cal. I do not recall ever reading where a P-38 pilot decided to shoot just his 20MM cannon because it was more effective, although most of the airplanes were equipped with separate machine gun and cannon firing buttons. I recall reading of one unit that used one button for both the .50 cal and 20MM, used the extra button for push to talk radio, and used the former PTT "horn button" in the center of the wheel to jettison the drop tanks rather than the previous location where it was hard to find when under duress.