particulate component hmx so that when the mixture is heated it has the texture of a viscous slurry to prevent precipitation of the particulate component of such an explosive mixture during the process of filling munitions items it is necessary to continually stir the molten mixture the apparatus 10 of a preferred embodiment of the present invention is provided with a double walled container having an outer generally rectangular wall 14 best seen in the vertical cross sectional view of fig1 an inner compartment is defined by wall 12 and is filled with the explosive material 16 the intervening space formed between the outer wall 14 and inner wall 12 as best seen with reference to fig1 is filled with a continually replenished supply of hot water 18 entering through inlet 124 and leaving through outlet 126 in a controlled flow at a controlled inlet temperature the explosive material 16 is therefore surrounded by and contained within a zone filled with hot water 18 maintained at a predetermined temperature high enough to keep explosive material 16 in a molten state one or more pneumatically actuated rotary air motors 20 provided with compressed air are mounted on a cover supported by cylindrical walls 14 and 12 and each has a vertically downwardly depending shaft 22 provided with stirring paddles 24 26 and.