Firearm-related injuries and deaths present a significant public health challenge in the USA, with high rates of firearm ownership, firearm injury and political divisiveness on prevention approaches. Secure firearm storage, especially during times of suicide risk, is an evidence-based, broadly supported approach. Partnerships with firearm businesses (known as ‘Gun Shop Projects’) can help promote secure storage messages in populations who might not readily interface with medical or public health agencies. To date, these partnerships have generally focused on civilian populations in local regions, yet military populations have high rates of firearm suicide. Here, we describe the development of the Pause to Protect programme, a partnership initiative designed to engage firearm businesses near US military bases with a primary focus on military Service Members and their families. The programme seeks to promote secure firearm storage and injury prevention through education, resources and voluntary storage services. Programme business partners, located near ten bases in 10 US states, received a financial stipend and ongoing technical assistance. The programme website offers business materials and customer education resources usable by any US firearm business, along with an online national map showing businesses willing to store firearms. Ongoing programme evaluation includes quantitative longitudinal surveys and qualitative interviews with businesses and other stakeholders. Programme establishment and ongoing engagement highlight partner and military base enthusiasm for this type of partnership to support education and voluntary action for firearm injury prevention in military and civilian communities. Areas for ongoing consideration include programme growth and sustainability.