Functional lifetime of gun propellants

19th International Symposium of Ballistics, 7–11 May 2001, Interlaken, SwitzerlandThe lifetime of conventional gun propellants is limited due to decomposition of nitrocellulose (NC). In general, research on ageing of propellants is mainly focussed on the safety aspects regarding storage of propellants. Decomposition of NC, however, not only leads to heat production that can result in run-away reactions, it also causes a decrease of the mechanical integrity of the propellant grains. In this investigation various properties of an SB and a DB gun propellant have been determined before and after artificial ageing. Simulations based on experiments with aged propellants show that the peak pressure may increase due to enhanced grain fracture after ageing. A number of parameters is selected from which the safe use of gun propellants can be determined. It is concluded that the lifetime of conventional gun propellants is not only determined by thermal degradation because changes of the mechanical characteristics may finally lead to unsafe employment.