Gore played all his rugby union for the unfashionable lower level club Blaina, though during this period the Welsh selectors would often choose tough manual workers to represent the forward positions.
His second game was against France and although a win for Wales, it was a poor Welsh performance caused by players being thrown out of position by the selectors decision to suspend Ossie Male on the trip to Paris.
Jack made his début for Salford against St Helens on 28 February 1925 as a Second-row before quickly being switched to loose forward with great effect.
Jack Gore played loose forward in Monmouthshire's 14-18 defeat by Glamorgan in the non-County Championship match during the 1926–27 season at Taff Vale Park, Pontypridd on Saturday 30 April 1927.
It is reported that he was instrumental in spotting the great Dai Watkins, also from Blaina, who followed Gore to Salford after his days as a Welsh International rugby star.