Weapons Malfunctions and the Reactivity of Iraqi Dust

The nearly ubiquitous presence of dust is a fundamental characteristic of the world's deserts and is therefore likely to impact military operations, especially the functionality of weapons and equipment. Desert dust commonly contains an abundance of fine particles susceptible to airborne deposition on and within equipment and weapons. Moreover, desert dust commonly contains several potentially chemically reactive constituents. A particular and critical issue that has evolved from U.S. combat experience in Iraq involves individual combat weapons (M4 and M16 rifles) jamming and failing to fire dependably. No specific causes were identified, but anecdotal information suggests that high levels of dust combined with the properties of standard Army cleaner, lubricant, and preservative may be the responsible.

This study was conducted to determine the physical and chemical properties of both Iraqi dust and soils, and to analyze how this dust reacts with gun lubricants. Samples collected within Iraq included representative dust sources based on the regional geology and samples collected directly from tactical vehicles. Analytical results indicate that the Iraqi dust contains abundant silt- and clay-sized particles as well as sufficient amounts of carbonates, sulfates, and chlorides; suggesting that there is a strong potential for corrosion, pitting, and related impacts to military equipment. Detailed Laser particle-size distributions of dust in a weapon lubricant matrix indicate a reaction that promotes the flocculation of sand-sized aggregates from silt-rich dust. These results indicate that the deposition of silt-rich dust within confining spaces of weapons and the exposure of this dust to gun lubricants can create sand-size aggregates which may be a principal reason for weapon jams.