The PU-21 (Russian: ПУ-21 Пулемёт с унифицированной подачей) is a 5.45×39mm machine gun designed by V. M. Kalashnikov and M. E. Dragunov between 1972 and 1977.

The PU-21's sights are graduated to distance of 1,000 metres (3,300 ft).

[1][2] The PU-21 prototypes were thoroughly tested by the Soviet Army in Leningrad, but military experts did not see convincing arguments for replacing the RPK and RPK-74 with the PU-21 design.

According to the Soviet military, the design was too complex compared to other weapons then in service, and failed to enhance combat effectiveness.

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