into propellant column, a process that would require either enormous energy (to move granules aside, almost instantaneously), or pulverization of all granules in a direct path toward bullet (so pulverized material could either "instantly" combust or somehow rearrange and thus move out of the way, which does not happen – nothing burns instantly and pulverizing material does not decrease bulk volume, the pulverized material could simply move into the pore spaces but that would take time and the momentum required would have to come form the much lighter gases, so the plume would run out of gas before moving more than a few-tenths-grain of propellant aside, which would halt penetration within a few-tenths-inch of flash hole!).
At extremely cold (arctic) temperatures, some types of flake propellant granules can become extremely fragile, with potentially tragic results. One 50 million round batch of NATO 9mm Pistol ammunition was loaded with such a propellant; under normal usage conditions, performance of this ammunition was perfectly normal; however, when these were laboratory tested at extremely low temperatures, peak pressure was monumental, suggesting that primer plume was driving entire charge against bullet base with sufficient force to pulverize many or all granules; upon ignition, the resulting pulverized propellant essentially detonated, which set up the famous standing-wave syndrome demonstrated in the Krupp tests, circa 1880, which is seen whenever the entire charge is ignited when positioned at either end of propellant chamber.