A novel approach to take into account the effect of compaction pressure on the shape of modeled hysteresis curves of self-developed soft magnetic composite cores is presented. The description relies on the introduction of an additional term in the so-called effective field, which is assumed proportional to the compaction pressure. The proposed model bears some resemblance to the Sablik’s extension of the Jiles–Atherton model, readily used in the studies of the magnetoelastic effect. Verification of the description is carried out using measurement data from self-developed iron-based composite cores.