The purpose of the Stop Arming Cartels Act of 2025 is to restrict the availability of .50 caliber rifles in the United States. The legislation aims to enhance public safety by prohibiting the importation, sale, manufacture, transfer, or possession of these powerful firearms, which are often associated with criminal activity, including drug trafficking. Key provisions of the act include a general ban on .50 caliber rifles, with specific exceptions for government use and for individuals who already lawfully owned such rifles before the law's enactment.