Shock tests of D16 Al alloy and Cr-3Ni-Mo-V constructional steel in single and reloading regimes show that dynamic recrystallization takes place only in the second case. The reloading regime initiates a tenfold increase in duration at the particle velocity non-uniformity stage as compared to the case with a single shock. This increase is sufficient for fulfillment of the well-known conditions for dynamic recrystallization to occur: γ ≥ 3, dγ/dt≥10 ⁴s ^-1, T≥0.4T _m.