In reverse order.
The British rushed their 20mm cannon into production because even eight 30calMGs were proven ineffective in the BoB. No AAF or USN fighters used 30s in WWII except the P-39. They were redundant on a plane with cannon and heavy MG centerline armament. And it's effective range was only 200yds. Sure there are mistakes in AHT, as with any reference. But you haven't proven that the EFFECTIVE range was any farther.
Oh, boy.
The British had been rushing the 20mm Hispano gun into production since 1938, if not earlier.
The British MARC company deed of partnership was registered on Jan 11th 1938.
The title deeds for the for the plots of land for the buildings were recorded in June of 1938 and the first prototype guns were being built and tested started in Jan 1939.
At the official opening of the factory in Jan 1939 the Duke of Gloucester fired the first British HS-404 cannon.
British were planning on putting 20mm cannon into existing designs and not wait for new designs in the Spring of 1940, well before the BoB.
Yes it took a while to get the numbers desired/needed.
Hundreds of German aircraft destroyed during the BoB might show a different result than "proven ineffective" this has been gone over many times. Likes the "ineffectiveness" of The Japanese 7.7mm (.303) guns.
As for the "effective range of the .30 cal or .303. How about you park you car out in field and let me shoot 40-60 rounds at it with a 30-06 or .303 rifle at 400yds (double the distance at which the .30 cal become ineffective) and then tell me how ineffective they are.
Switching the goal post on the heater???
Did the British ask for it or take what was offered? You claim the British asked for it. Was the new heat system offered to the French? Did the British change it back?
The IFF was useless in 1942 NG because there was no accurate radar until fall. The British DID order it but once the P-400s were diverted to NG the IFF would have been removed. To save the weight.
Another switcheroo. You claimed the British added unneeded weight to get out of the contract. IFF was needed in 1940-41 and 42 over Britain and in the contested space over the channel.
First, nobody can prove British intent. I can't prove that the British intended to make the P-400 too heavy to make the performance guarantee. You can't prove that they didn't. But they certainly knew that a 7850lb P-400 with a 1150hp engine couldn't go 400mph, especially when their contemporary 6600lb Spitfire V would only go 371mph with a more powerful engine. And Bell knew that the P-400 couldn't make the guarantee, certainly not at 7850lbs. Who's fooling who? A P-400 tested in the US did go 371mph albeit at a lower altitude.
changing your tune? You claimed the British made the P-400 too heavy so as to get out of the contract, Now you are saying you can't
prove it. But you still want us to believe it.
As for the British KNOWING that the 7850lb P-400 with 1150hp engine couldn't go 400mph?
If they knew that they should have told North American to quit fooling around with the NA 73 and just build P-40s.
British tested an 8600lb Mustang I at 370mph with an 1150 hp (?)engine.
Aircobra tested in England was 800lb lighter, used the same engine and was 15mph slower.
Power vs drag determines speed, not power vs weight.
Expecting a smaller, more streamline plane, even if heavier, to make a higher top speed than a larger/older/higher drag airplane was not unreasonable. Difficult but not impossible.
Bell flubbed it, big time.