Direct proof of use
The PM-43 appears in the Syrian Civil War record under the M-1943/M43 designation used by Action on Armed Violence. AOAV's Syria Dirty Dozen project identified heavy mortars like the M-1943 as among the commonly used explosive weapons in the conflict and stated that both state and non-state actors regularly used mortars.
AOAV's later Wide-Area Impact mortar study gave the weapon-specific inventory link: it described the M-1943 as one of the mortar types in use in Syria, said Syria had hundreds that had been shipped over time by Russia and Bulgaria, and treated Syrian border-area mortar fire as part of the conflict's repeated use of inaccurate indirect-fire weapons.
Sources: AOAV Syria Dirty Dozen, AOAV M-1943 Mortars, AOAV Syrian-Jordanian Border Mortars
Battlefield role
In Syria, the supported role for the PM-43/M-1943 family is heavy mortar fire support by indirect fire. The weapon was relevant to the war because 120 mm mortars could be moved and fired from range while still reaching several kilometers, making them useful to forces fighting around towns, border areas, and other populated or semi-populated front lines.
AOAV's Syrian-Jordanian border overview attributed mortar use in the conflict to many parties, including the Syrian army and fighters allied to Islamic State. The same overview recorded that mortar fire originating inside Syria crossed into all five neighboring border countries and investigated fifteen Syrian-to-Jordanian strike impacts from 2012 to 2015, while noting that it was often difficult to verify the exact munition type in individual border strikes.
Sources: AOAV Syrian-Jordanian Border Mortars, AOAV M-1943 Mortars
Evidence limits
The strongest public claim is that the M-1943/M43 120 mm mortar family was in use in Syria and that mortars were used by Syrian government forces and Islamic State-aligned fighters. The available AOAV sources do not provide a dated firing log that ties a specific PM-43 tube to a named unit, target, or casualty incident.
This page therefore treats the PM-43 record as documented Syrian Civil War fielding and mortar fire-support use, not as proof that every AOAV-recorded mortar strike involved this exact model. The specific side assignment follows AOAV's attribution of mortar use to the Syrian army and fighters allied to Islamic State.
Sources: AOAV Syrian-Jordanian Border Mortars, AOAV M-1943 Mortars, AOAV Syria Dirty Dozen