One hundred firings were made using a Remington model 870, 12-gauge pump action shotgun; ammunition used was commercially available 12-gauge Winchester-Western, 00 buck, shot shells. In 20 shots, the shotgun barrel temperature had been lowered; in 20 shots, the shell temperature had been lowered; and in 60 shots, the barrel and shell temperatures were maintained at ambient values. The results showed that temperature effects may have an undesirable impact on estimation of range-of-fire of shotgun pellet patterns. Specifically, shells that have been exposed to colder temperatures may produce pellet patterns on a much more restricted range than those stored under normal conditions. The reduced temperature produces a slower gun powder burn time, reduces the pressure in the barrel chamber, and lowers the velocity of the shot. As a result, there is less natural deformation of the pellet, less air resistance, and smaller dispersion of the pellets. Therefore, estimation of range-of- fire must be made with knowledge of relevant conditions under which shotgun pellets were stored. 4 tables, 2 figures, and 6 references