When a mechanical case failure is encountered during the firing of aluminum cased ammunition, particularly with high-pressure, high-performance weapon systems, the failure of an aluminum cartridge case is characterized by a large efflux of very luminous gases at the breech of the weapon, the serious erosion of the cartridge case, and often, the inability of the weapon to function properly thereafter. Thus, this failure may result in serious harm to the rifleman and damage the weapon....
...it was found that ... a four thousands deep longitudinal scratch would, upon firing, result in "burn-through".