TUL-1 light machine gun still in use in Vietnamese army.

While similar to the Soviet RPD/RPK, the TUL-1s were actually Chinese Type 56 assault rifles but with the stock of an RPK, barrel/sights from an RPD, and 30 round magazine used on the AK-47/Type 56. On rare occasions, they had 40 round magazines but almost never the 75 round magazine typically used in the RPK.
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TUL-1 light machine gun in the hands of a Vietnamese soldier (Picture source: VietDefense Facebook page/Lê Khang)

Because it used the frame of a Type 56 assault rifle, the TUL-1 body was thin, only 1 mm compared to the 1.5mm of an RPK. It was also heavier and had an inferior rate of fire compared to the RPK - the firing rate was only slightly better than that of an AK-47/Type 56. However, the effective range of the weapon was successfully increased.

It has a very low rate of fire and a strong recoil, but it compensates for this with high damage and very fast (for a machine gun) reloading. With a double magazine, it has a 1-second reloading record for its class, which, taking into account the high damage and good accuracy of shooting, makes it a very deadly weapon.

Thousands of TUL-1 LMGs were manufactured for use on the battlefields between 1970-1972. Production of the TUL-1 ended after Vietnam obtained production rights to the RPK itself.