Sand Testing An AR15, M1A, And MAS 49/56

As a followup to our original mud testing, we took out AR, M1A, and MAS 49/56 to a dusty part of the range and used an air compressor to shower them with blowing sand and dirt while firing. Which ones would be able to keep running, and for how long? No AK in this one, we’re considering visiting that topic per many, many requests. This testing was inspired by archival footage of Owen SMG testing in WWII: