At the end of the First World War, the French Ministry of the Interior recommended that prefects tolerate demobilised soldiers’ possession of war souvenirs, despite the formal prohibition on military weapons in force since 1834. During the 1920s, these weapons were displayed in town halls to commemorate the war, while veterans also kept them in their attics as proof of their bravery. However, less than fifteen years later, alarming concerns emerged about the presence of weapons of war in private homes, as the arming of anti-republican revolutionary groups came under increased scrutiny. Fear of a coup d’état – particularly acute after 6 February 1934 – led to searches of the homes of souvenir collectors. In this paper, I investigate the rise of private collections of war memorabilia in the 1920s, followed by their decline in the 1930s, when such collections came to be viewed as potential stockpiles of guns in anticipation of insurrection. This case study demonstrates how the collecting practices and emotions of war relic owners, as well as the material nature of weapon collections, played an essential role in defining what constituted a legitimate war souvenir. The maintenance, oiling, and cleaning of weapons was interpreted as a sign of antirepublican activity by the authorities, who were increasingly unwilling to tolerate the presence of First World War rifles in French homes.