Soviets/Warsaw Pact nations ALL used 7.62x54r, in Light ball, with a silver tip and a heavy ball with a Yellow tip.
The Chinese manufactured and boughtfrom other countrys and issued both heavy and light ball, but once the Communists consolidated power, by the late 50's they only manufactured Light ball.
The light ball, either silver tipped or uncolored, was used for light/medium machineguns and rifles
When the Maxim macheingun ( which ran much better using heavy bullets) was phased out of service in the 50's, and the PK/PKM adopted, tactics for medium /heavy machineguns changed as well, so the Yellow tipped , heavy ball was dropped from service use.
The dropping of the second type of round ment a color code was no longer needed and light ball was the single issued round and was no longer color coded.
Heavy ball was never hot loaded, its the extra bullet weight you feel in recoil, not a heavier load of powder.
Th only "Hot" 7.62x54r was for aircraft machinegun use only,and it was part of achieving a very high cyclic rate for air combat.
Alot of countrys used up their heavy ball by repacking it on stripper clips and issuing it as training ammo or for sale on our market.
Soldiers always use whats issued to them or what they have on hand.
the PSL will use both types with no damage, but the SVTs gas system gets bent and pounded, so its best not to use any but Light bullets in them.