The purpose of this paper is to examine a scalable secure firearm storage intervention in the U.S. National Guard (NG) in preventing firearm injury and suicide. A study among firearm-owning members of the Mississippi NG testing Project Safe Guard (PSG), a 10 to 15 min lethal means counseling intervention, found that PSG increased self-reported secure firearm storage practices. Here, we sought to examine a "real world" rollout of a modified PSG program in the NG in which NG members were trained to understand the importance of lethal means safety and to deliver PSG to Guardsmen peers within their units. The PSG team collaborated with the NG to identify 4 states for the rollout; for each state, the NG was responsible for identifying key personnel ("facilitators") who would receive the training. Team members provided in-person training at 5 locations across 4 states (AZ, GA, IA, and NV) from January to April 2023. Attendees were provided with combination trigger locks or cable locks and evaluation instructions. Questionnaires were administered to training attendees via REDCap at pre-training and post-training. We conducted descriptive and comparison statistics of questionnaire data. A total of 186 facilitators were trained at 5 in-person training locations across 4 states (AZ, GA, IA, and NV) from January to April 2023; data collection concluded in August 2023. There were 137 pre-training responses (74% pre-survey response rate) and 88 post-training responses (64% response rate from those who took the pre-training survey). Findings demonstrate increases in self-reported knowledge, attitudes, and beliefs regarding firearm injury and suicide and a reported desire to store personal firearms more securely. The adapted version of PSG shows promise as a relevant and acceptable intervention among Guardsmen to enhance knowledge and attitudes regarding firearm suicide, increase secure firearm storage practices, and normalize conversations about firearm suicide prevention among peers. This intervention seeks to frame firearm suicide prevention within a culture of safety, complementary to the existing prevention methods and training within the NG.