Quote:
Originally Posted by Sven
You'll shoot the whole RAF's stock of DeWildes in no time  |
You're dead right Sven.
A Captain or later Major Dixon of the Royal Arsenal (responsible for small arms ammunition) was entrusted to sort out (remake) the De Wilde ammunition suitable for British manufacturing processes. Hence, Dixon (without instruction or permission from superiors) found his own solution after much personal trial and error. And, just in time too. His Mk 7 wasn't put into production until May 1940, and wasn't available at all till June 1940, and wasn't in general widespread use till August 1940.
1940 First production .303” Ball Mk 7 at Royal Ordnance Factory (ROF) Radway Green.
1940 First production of .303” Ball Mk 7 at ICI Agency factory, Standish (K2).
1941 Last .303” incendiary cartridge (B Mk 7) approved for service.
In firing tests, the Mk 7 had a 20% success rate in setting fuel tanks alight, twice that of the older Buckingham or the equivalent German 7.92 mm incendiary rounds, and also had the happy side-benefit that the flash of ignition on impact told the pilot that he was on target. This effect was very popular.
The RAF in 1940 preferred to load each .303 fighter gun with only one type of ammunition (easier than mix and matching ammunition in belts by hand when in a hurry during a desperate war).
The Dixon Mk 7 ammunition was first issued to squadrons in June 1940 and was at first in short supply. The initial fighter loading being one gun firing Dixon incendiary (when available), two guns with the old 1929 issue Buckingham incendiary/tracers (British gun camera film from the Battle of Britain often clearly shows the smoke trails of this round), and two guns with armour-piercing, and three with plain vanilla "ball" rounds with lead cores. This didn't change till 1942, then the standard loading for fixed guns was half with AP and half with incendiaries.
In the Battle of Britain, the performance of .303 ammunition was initially adequate but it was found that the German bombers often survived large numbers of hits. The reason became clear in further tests which involved firing .303 and German 7.92 mm armour-piercing ammunition against the fuselage of a Blenheim light bomber from behind – not the toughest of structures, and with only a 4 mm armour plate protecting the gunner. This AP ammunition could normally penetrate up to 10-12 mm of armour plate, but it was found that the aircraft structure it had to plough through before reaching the armour deflected, absorbed or disrupted the flight of the great majority of the bullets, and of those which reached the armour, very few had enough energy left to penetrate it. Some improvement was achieved by reducing the gun harmonisation range from 400 to 250 yards in order to concentrate the firepower of the RAF's fighters, but it was clear that a more powerful gun was needed. This eventually arrived in the form of the 20 mm Hispano.
The Dixon, Mk 7 / De Wilde bullet had no trace effect whatsoever.
There's a good read in a book called "One Perfect Summer", or something like that, about Captain Dixon.
http://cartridgecollectors.org/cmo/cmo07feb.htm
http://1914-1918.invisionzone.com/fo...owtopic=104583
A timeline of .303 development...
http://www.milsurpafterhours.com/bb/...c.php?f=3&t=79
http://www.quarry.nildram.co.uk/RAF%20guns.htm