He arrived at Plymouth on 17 April 1750, putting in there on account of the inclemency of the weather, which the men were unable to stand, being, he wrote, entirely naked.
He was afterwards appointed by Sir Edward Hawke, in rapid succession to the Chesterfield, the Deptford, and the Trident; was then sent home as a witness at the trial of Admiral Byng, and in April 1757 was appointed to the Southampton, a 32-gun frigate, in which, off Portland, on 25 July, he fought a severe action with two French frigates of superior force (Laughton, Studies in Naval history, p. 333), and succeeded in beating them off.
With better fortune he met, on 12 September, the French frigate Émeraude, which he captured after a sharp action of thirty-five minutes' duration, and brought into Falmouth.
During the following year he was still employed in Channel service, in the course of which he captured two large privateers; and on 28 March 1759, being in company with Captain Hotham in the Melampe [see Hotham, William, Lord], on a cruise in the North sea, met and engaged the 40-gun French frigate Danae, which, after a hard-fought action, lasting all through the night, struck her flag in the morning.
Gilchrist was shot through the shoulder by a one-pound ball, a wound that for the time endangered his life, and rendered his arm permanently useless.