A comment on “Plasticity, ductile fracture and ballistic impact behavior of Ti-6Al-4V Alloy” by Wu et al. (2023), Int. J. Impact Eng. 174:104493

•This manuscript highlights the difference between two common models: Recht-Ipson model and Lambert-Jonas model.•We also point to a common misunderstanding, made by many authors, regarding their interpretation of their ballistics results. We discuss a common misunderstanding made by many authors, regarding their data analysis for blunt rigid projectiles perforating thin metallic plates. The problem with their analysis is that they use the empirical relation of Lambert and Jonas (1976), which was suggested for eroding projectiles penetrating thick plates. Instead, they should use the physics-based model of Recht and Ipson (1963) to account for their data. The paper of Wu et al. (2023) is one of these works, and we use their ballistics results to demonstrate the benefits of the R-I model to account for their data.