The study is directed at understanding how organic lead salts (at the 1% level) alter the burning mechanisms of double base propellants to produce large (up to 300%) burning rate increases (super-rate burning) and domains of reduced burning rate pressure and temperature sensitivity (plateau burning). Investigations were carried out with nitrocellulose and trimethylolethane trinitrate (TMETN) double base propellants with systematic variations in additives (including lead powder, lead oxide, lead salicylate, copper powder, copper salicylate, finely divided carbon, and oxamide), particle size, and degree of dispersion. Diagnostic experiments (from 0.1 to 100 atm) examined burning rate behavior, gas-phase structure, burning-surface structure, temperature profiles in the reaction zones, and global effects. The portion of decomposed organic molecules which appears at the surface in the form of carbon rather than readily oxidizable aldehydes reduce the effective fuel to oxidizer ratio (aldehyde to NO2).