Summary: Numerical simulations are done of Langevin dynamics for a uniform-orderparameter, field-swept Landau model, \(\Phi= -|a/2|m^2+|b/4|m^4-mh(t) \), to study hysteresis effects. The field is swept at a constant rate \(h(t)=h(0)+ht\). The stochastic jump values of the field \(\{h_J\}\) from an initially prepared metastable minimum \(m(0)\) are recorded, on passage to a global minimum \(m(\tau)\). The results are: (a) The mean jump \(h_J(h)\) increases (hysteresis loop widens) with \(h\), confirming a previous theoretical criterion based on rate competition between field-sweep and inverse mean first-passage time \(\langle\tau\rangle\) (FPT); (b) The broad jump distribution \(\rho(h_J,h)\) is related to intrinsically large FPT fluctuations \((\langle\tau^2\rangle-\langle\tau\rangle^2)/\langle\tau^2\rangle \sim O(1)\), and can be quantitatively understood. Possible experimental tests of the ideas are indicated.