From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph showing weight calculations for alternative gun installations on Spitfire aircraft.
| Identifier | ExFiles\Box 176\1\ img031 | |
| Date | 17th July 1940 guessed | |
| ALTERNATIVE GUN INSTALLATION FOR SPITFIRE AIRCRAFT Based on weight of 8 - .303 Browning Guns + 300 Rounds per Gun. 8 Guns. 7 Guns. 6 Guns. 5 Guns. 4 Guns. 3 Guns. 2 Guns. 1 Gun Weight in Pounds 100 200 300 400 500 600 700 800 | ||