Complex sentence: The Type 92 (Semi-rimmed) 7.7 mm (7.7 mm x 58 SR) was developed as a machine gun cartridge and was primarily used with the Type 92 Heavy Machine Gun and the Type 89 flexible and fixed aircooled machine guns used on Japanese planes.
Split into simpler sentences: The Type 92 (Semi-rimmed) 7.7 mm (7.7 mm x 58 SR) was a machine gun cartridge and was primarily used with the Type 92 Heavy Machine Gun. It was developed from the earlier Type 89 flexible and fixed aircooled machine guns used on Japanese planes.