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).
Sizes and locations for drilling, boring, reaming, and rifling operations on 40 m/m barrels.
| Identifier | ExFiles\Box 176\3\ img070 | |
| Date | 20th October 1940 | |
| To Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/Cy c.c. Rn.{Mr Robinson} 40 m/m Barrels. In reply to your Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}1/DN.18.10.40., we attach tabulated particulars in regard to sizes and locations for the Drilling, draw boring, reaming and rifling operations on our 40 m/m Barrel. This information has been taken from our operation layout which covers the exact procedure as carried out on our barrels by the Royal Ordnance Factory, Nottingham. The attached blue print illustrates the locations as used on the various special machines and is for record purposes. The following proposed cable represents the minimum wording consistent with the essential information required. “Forty Millimeter Barrel sizes and locations stop Drilling muzzle 3.000 diameter. 4 point adjustable running steady Breech 5.000 dia 4 jaw chuck stop. First draw bore muzzle 2.875 dia 4 point adaptor Breech 5.000 dia. 4 point adjustable running steady stop. Second draw bore muzzle 2.875 dia. 4 point adaptor Breech 4.325 diameter 4 point adjustable running steady stop. Draw ream muzzle 2.875 diameter 4 point adaptor Breech 4.160 diameter 4 point adjustable running steady stop. Rifling muzzle 2.875 diameter 4 jaw chuck Breech 4.125 dia. 4 point adjustable indexing adaptor stop.” HPS{Horace Percy Smith - Experimental Factory Mgr}/Cy | ||