Crystals of γ‐HNIW were transformed into crystals of ε‐HNIW by application of a drowning‐out process in the presence of different additives, namely ethylene glycol, triacetin, and aminoacetic acid. They show different effects on the crystal morphology of ε‐HNIW and cause less angular and more regular structures. Investigation of the sensitivities of the different ε‐HNIW crystals shows that their angles and regularity have an influence on the impact sensitivity. Aminoacetic acid selectively inhibits the growth of individual ε‐HNIW crystal faces to modify the morphology into spherical shape, these ε‐HNIW crystals are of much lower sensitivity, even compared with general RDX and HMX explosives.