The (p,2p) reaction on 40Ca at incident proton energy of 300MeV is examined in the formalism of finite-range relativistic distorted-wave impulse approximation (FR-RDWIA). In comparison to conventional t-matrix model of Love–Franey, a new form of nucleon–nucleon t-matrix effective interaction is derived at 300MeV using Reid soft core potentials for isotopic spin one and taking into account the finite-range effects in the p−p interaction at knockout vertex. In comparison to the conventional finite range nonrelativistic and relativistic formalism, the present formalism with a new version of p−p t-matrix is effectively reproducing the shape of cross-section energy distributions for 1d3/2, 1d5/2 and 2s1/2 states for asymmetric angle pair of 30∘–55∘. Discrepancies between the experimental cross-section data and finite range theoretical calculations at Ep=300MeV are reasonably resolved in the present approach. Without any adjustable parameter of bound state, the obtained spectroscopic factors are in reasonably good agreement with the relativistic and nonrelativistic theoretical predictions by (p,2p), (e,e′p) and (d,3He) analysis.