China entered the Korean War armed with a mind-staggering array of weapons collected over fifty years of civil and international war. The logistics for maintaining such an armory during repeated ferocious battles were impossible. China began purchasing and copying Russian weapons extensively after the first year of the Korean War, and also building her own versions. This Type 50, their version of the Soviet PPSh 41, was one of the best and earliest examples.
With such an exposed entrance, this would have been more of an Observation Post covering a valley or other wide expanse. If attackers actually came within a few hundred yards of this position it would have been untenable. The large, concussion type potato masher hand grenade would have been for the unexpected, not part of a planned defense.
