Representation of live-fire energetic residues from insensitive mortar munitions using command-detonation testing

Command (i. e., static) detonation is critical for testing munitions early in the acquisition process, however its representation of energetic residues produced during live fire has not yet been assessed. Here we measured energetic residue deposition rates on snow from live fire of 60 mm and 81 mm IMX-104 mortar munitions and then compared results with previous command-detonation tests of the same munitions. Mean live-fire deposition rates of IMX-104 compounds were: 3800 mg NTO, 34 mg DNAN, 12 mg RDX, and 1.9 mg HMX per 60 mm cartridge (n=9); and 8000 mg NTO, 60 mg DNAN, 20 mg RDX, and 2 mg HMX per 81 mm cartridge (n=13). The predominant residue compound NTO was accurately estimated by command detonation for the 60 mm munition (p=0.92) but was significantly underestimated for the 81 mm munition (p<0.0001). The minor residues of DNAN and RDX were relatively well estimated by command detonation for the 81 mm munition (p=0.07 and p=0.014, respectively), but both were significantly underestimated (p<0.0001) for the 60 mm munition. Despite some of these differences, the ability demonstrated here for command detonation to predict live-fire residue deposition rates to the correct order-of-magnitude supports its utility in assessing environmental impact.

Automated summary

Command detonation is critical for testing munitions, and it can provide a relatively accurate prediction of residue deposition rates during live fire, supporting its utility in assessing environmental impact.