The flow of RX-08-FK, a mostly organic, high-energy, paste-extrudable explosive containing about 75% suspended solids, was experimentally studied. The paste was forced through long capillary tubes in a specially designed, double-piston rheometer at temperatures ranging from -54 to +74 degrees C, and at nominal shear rates at the tube walls from 50 to 40000 s(-1) preconditioned for many hours to achieve the desired experimental temperature and the rheometer itself was enclosed in a preconditioned temperature-controlled chamber. We found the paste to be pseudoplastic with significant yield stress and entrance effects. The results of 176 runs at temperatures of -35 degrees C and higher were fitted by an empirical model much like the original model suggested by Herschel and Bulkey, modified to include a factor correcting the stress for the substantial entrance loss experienced with this paste. The observed stresses at -54 degrees C were substantially higher and less shear dependent than those extrapolated from the above model; these differences may relate to the fact that the glass-transition temperature of RX-08-FK is approximately -60 degrees C.