1693, Thomas Povey, I. The Method, Manner and Order of the Transmutation of Copper into Brass, &c. By Thomas Povey, Esq; Brought into the Royal Society, of which He is a Fellow., The beſt Guns are not made of malleable Metal, and cannot be made of pure Copper or Braß; but it is neceſſary to put in courſer Metals to make it run cloſer and ſounder, as Lead and Pot-metal. ... About 20l. of Lead is uſually put into 100l. of Pot-metal; but about 6l. is ſufficient to put into 100l. of Gun-metal.
1702, The Act of Tonnage & Poundage, and Rates of Merchandize, with the Further Subsidy; the Old Import; the Additional Impost; and All Other Duties Relating to Her Majesties Customs, Now Payable upon Any Sort of Merchandize Imported or Exported. ... Chapter An Abridgment of Several Statutes Now in Force and Use, Relating to Her Majesty’s Customs, which were Made before the Act of Tonnage and Poundage, 12 Car. II note: Braſs, Copper, &c. Prohibited to be Exported, Braſs, Copper, Latten, Bell-Metal, Pan-Metal, Gun-Metal, or Shruff-Metal, whether clean or mixed, carried beyond Sea, forfeits double the Value thereof; (Tin and Lead only excepted) the Informer half, ...
1874, Spons’ Dictionary of Engineering, Civil, Mechanical, Military, and Naval; with Technical Terms in French, German, Italian, and Spanish Chapter ARTILLERY, Phosphorus is known to improve the strength of copper, and to make it cast soundly. Abel, chemist to the British War Department, stated before the Institute of Civil Engineers, that he had made some experiments upon the combinations of phosphorus and copper, and "had found that by the introduction of a small proportion, say from 2 to 4 per cent., of phosphorus into copper, a metal was produced remarkable for its density and tenacity, and superior in every respect to ordinary gun-metal. ... The experiments alluded to were merely preliminary, and had been, to a certain extent, checked by the improvements since introduced in the construction of field-guns, which had led to a discontinuance of the employment of gun-metal."
1999, Dominique Sigaud, Somewhere in a Desert Chapter , From his window on to the courtyard he watched the low, gun-metal sky over Châteauroux and the bare barrack trees, and was perversely reminded of the harsh desert light, the heat, the colours of the dunes at evening; the overcast skies.
