Stamper decided to join the Royal Air Force after experiencing a biplane land close to his school in Settle Yorkshire. He joined up at RAF Cardington, before being posted overseas to Southern Rhodesia. He returned to East London 48 Air School to train as a bomb aimer, before returning to Rhodesia with 101 Squadron, where he unfortunately caught malaria. After losing his crew whilst in hospital he was posted to 100 Squadron at RAF Grimsby, Lincolnshire.

Stamper was stationed in Bulawayo South Africa for desk-based training in the IWT (Initial Training Wing) then at Mount Hampden for navigation and flying training school. He returned to England and went to Whitley Bay for more training, then formed a crew with two others. Their first operation was to sink a large German force off the Dutch coast.  He flew in a Lancaster Bomber explaining how safe it felt compared to other bomber aircraft.

Stamper describes his experiences in the Nuremberg raid where Bomber Command lost ninety-seven out of a force of two hundred and fifty after passing the main route of enemy night fighters. He recalls the Dresden raid targeting railway martialling yards, which resulted in a firestorm.

Stamper later took part in Operation Manna, dropping food parcels to the starving Dutch population, and remembers tying chocolate for the children in his handkerchief. After the war, the crew felt something was missing for them, so they formed the 100 Squadron Association and Stamper became the first treasurer. The Association unveiled a memorial at Holton le Clay near RAF Grimsby with Stamper giving the dedication each reunion.