The article analyzes the role of the state in formulating social conventions about firearms in Brazil. We selected Law 10.826/2003, passed during the first Lula Government (2003-2006),as the empirical dispute, and also we analyzed eight presidential decrees from the first year ofthe Bolsonaro Government (2019). In the methodology, we analyzed the legal framework based on the studies of Steiner and Trespeuch, about contested markets; Bourdieu, about the state and the concept of social convention, by Mary Douglas. The results indicate that the state has influenced the production of predispositions and that the disarmamentist social convention, produced during the Lula Government, has been challenged, generating disputes that go beyond the normative perspective.