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).
The results and remarks from a firing trial, including accuracy, wear, and performance issues.
| Identifier | ExFiles\Box 176\1\ img185 | |
| Date | 1st May 1941 guessed | |
| -2- 4. Results. The full results are attached as Appendix B and C, a part of which is summarised as follows :- (a) Accuracy at 300 yards. Horizontal Vertical Feet. 7 single shot diagrams 1.00 0.60 7 automatic shot diagrams 0.80 1.90. (b) O/V at 90' 2419 5/18 ft/sec. (mean of ten shots). Wear. At Commencement of trial. At Conclusion of trial. Horizontal 0.004 0.006 Vertical 0.005 0.006 Number of rounds fired during trial - 177 rounds. 5. Remarks. The accuracy results do not show the Optimum of which the gun is capable because the mounting supplied by Messrs. Rolls-Royce was not sufficiently steady. No attempt has been made to summarise the functioning as it is felt that this can only be followed shot for shot as shown in Appendix B. Temperatures were not recorded in view of the unreliable functioning of the gun. Firing was continued to find out the greatest buffer pressure at which satisfactory functioning could be obtained at depression, so that a common pressure could be arrived at for both elevation and depression. This appears to be approximately 355 lbs. with the adjustable orifice opened to 6 turns. On five occasions, the mal-ejection stoppages were a fault of the mounting supplied and not of the gun itself. These are the ones affected by Modification 3 as noted in Appendix B. cont'd.{John DeLooze - Company Secretary} | ||