In the present work, molecular dynamics (MD) simulation has been employed to understand the interaction between an edge dislocation and copper precipitate in austenitic stainless steel. The effect of precipitate size and spacing on the shear strength was studied. The mechanism controlling the shear strength was found to be either trailing partial detachment or leading partial detachment from the precipitate, which depends on the precipitate size and spacing. Besides, modulus misfit strengthening was found to be the prime contributor to the overall strength of the present alloy. Based on the simulation results, the existing Russell-Brown model for modulus strengthening was modified for the present case. The proposed model was used in combination with experimental results and DICTRA to predict the precipitation strengthening due to copper rich precipitates in a copper containing austenitic stainless steel, 304HCu with ageing time. The predicted values obtained from the modified Russell-Brown model were found to be in reasonable agreement with the experimental data. Further, the results were also verified using dislocation dynamics (DD) simulation for predicting the strengthening for a random distribution of precipitates.