text: Initial temperature of propellant. In summary, however, most formulations have a burn rate between 1–3 mm/s at STP and 6–12 mm/s at 68 atm. The burn characteristics (such as linear burn rate) are often determined prior to rocket motor firing using a strand burner test. This test allows the APCP manufacturer to characterize the burn rate as a function of pressure. Empirically, APCP adheres fairly well to the following power-function model:
  It is worth noting that typically for APCP, n is 0.3–0.5 indicating that APCP is sub-critically pressure sensitive. That is, if surface area were maintained constant during a burn the combustion reaction would not run away to (theoretically) infinite as the pressure would reach an internal equilibrium. This isn't to say that APCP cannot cause an explosion, just that it will not detonate. Thus, any explosion would be caused by the pressure surpassing the burst pressure of the container (rocket motor).
  Model/high-power rocketry applications
  Commercial APCP rocket engines usually come in the form of reloadable motor systems (RMS) and fully assembled single-use rocket motors. For RMS, the APCP "grains" (cylinders of propellant) are loaded into the reusable motor casing along with a sequence of insulator disks and o-rings and a (graphite or glass-filled phenolic resin) nozzle. The motor casing and closures are typically bought separately from the motor manufacturer and are often precision-machined from aluminium. The assembled RMS contains both reusable (typically metal) and disposable components.
  The major APCP suppliers for hobby use are:
  Aerotech Consumer Aerospace
  Cesaroni Technology
  Loki Research