The Nikitin-Sokolov PN1, also known as the TKB-521, is a prototype general purpose machine gun.
History
The PN1 was designed by two designers, Grigory Nikitin and Yuri Sokolov and passed field tests in 1958. It was to be the standard-issue general purpose machine gun for the Soviet military. All was going well for the PN1 until a group of designers from IZMEKH and submitted their machine gun design; the IZMEKH design won out as it was said that it was cheaper and more reliable than the Nikitin-Sokolov design, and the PN1 faded into history. Nikitin, Sokolov and V. I. Volkov would later work together to produce the very successful NSV machine gun.
Design Details
The PN1 is gas-operated with a rotating bolt. The weapon feeds from the right, as with most Russian machine guns of the time.