Complex sentence: Using this system allows the FX-05 to fire at it's extremely fast rate of 2,100 RPM (Citation needed) although when fired fully automatically the mechanism self-regulates itself down to 750 RPM after the first three rounds.
Split into simpler sentences: Using this system allows the FX-05 to fire at it's extremely fast rate of 2,100 RPM. When fired in fully automatically mode the mechanism self-regulates itself down to 750 RPM after the first three rounds.