In ihe early 1980s foreign countries started using add-on explosive reactive armour (ERA) to improve protection against shaped-charge ammunition. ERA consists of steel containers with metal plates spaced by explosive layers. When an anti-tank rocket hits an ERA container, the shaped-charge jet detonates the explosives. The metal plates and explosion effect disperse ihe shaped-charge jet, which considerably reduces armour penetration.
Despite the fact that ERA was first developed in the USSR (the Moscow-based Stali Researc h and Development Institute), it was for the first time used on the battlefield by Israel during another war in Lebanon. The Rafael company developed the Blazer add-on explosive reactive armour and mounted it on Israeli M60A1 and Merkava main battle tanks. As a result, the efficiency of man-portable anti-tank rocket launchers, firing HEAT rounds, was drastically affected in the course of combat operations in Lebanon in 1982.
The world's first tandern HEAT warhead round for a rocket launcher was developed by the Bazalt State Research and Production Enterprise (leading engineer A. B. Kulakovsky) and fielded with the USSR Armed Forces in 1988 under ihe designation of PG-7VR (R stands for 'Rezyume' — the codename of the research and development project). This round is capable of defeating tanks equipped with add-on ERA.
The PG-7VR tandem warhead consists of two HEAT warheads — the first or precursor charge with a calibre of 64 mm and the main warhead with a calibre of 105 mm. The front warhead detonates explosives of the ERA. The main warhead, accommodated at a certain distance from the precursor charge, which ensures its safety during the explosion of the front warhead and ERA. detonates with a slight delay.
This arrangement allowed the rocket to penetrate 600 mm of the core armour after defeating ERA. However, a considerably heavier round resulted in a reduction in the effective rage of fire down to 200 m.
When a new round with totally different ballistics entered the inventory of the RPG-7V launcher, it became necessary to modify the sight (the new sight was designated PGO-7V3) and fit the rocket launcher with a detachable folding bipod, just like on 'night' versions of the rocket launcher. The new PGO-/V3 optical sight has range scales for firing all types of rounds, including the TBG-7V thermobaric round and the OG-7V fragmentation round developed later on. The irons sights were modified as well.
The new rocket launcher was designated RPG-7V1. while its airborne variant was designated RPG-7D2.