The paper deals with the competing models of internal surfaces heating of gunpowder elements channels in a liquid under impact compression. The first model is based on impact volume compression of the air in the channels at impact, and the second model is based on the action of shear stresses arising due to viscous friction of a liquid flowing in the channels under the influence of external pressure. The paper presents experimental data on the character of ignition site in the channels based on the assessment of artillery pyroxylin powder 12/7 sensitivity equivalent to the impact drop-hammer.