Learning the RPG-7

Weapons Man

Obsolete (or at least obsolescent) in Russian service, the RPG-7 continues to serve with scores and scores of armies worldwide. Every Afghan armed force, regular or irregular, since about 1980, has used this versatile and powerful weapon.

This DOD B-roll video shows Marines training members of the Afghan National Army in the loading and firing of the RPG on 24 August 2011.  This was a train-the-trainer event; the Afghans in this video were being trained as small arms assistant instructors.  

The Afghans are speaking Dari, not Pushtu. They’re firing with iron sights, not the optic (the optic takes days to train. Even the iron sights have two settings, normal and low-temperature [sub 0ºC]), and they’re using OG-7V HE/Frag warheads. This is that bad boy, in promotional makeup:

The rough midpoint of the rocket (that shiny band) is where it initiates. The firing pin of the RPG-7 is located on the ventral side of the weapon; the hammer strikes it in the “up” direction and it strikes an initiating primer. Since the primer is in only one position around the 360º circumference of the booster, the round is provided with a small lug (the “indexing lug”) that fits into a notch in the muzzle (the “indexing notch”). An RPG round that is not fully indexed and seated will not fire. The fins are contained inside the booster charge, This very nice 3D render of one of the RPG files available at “Turbo Squid,” a 3D file vendor, shows you how the fins work. It doesn’t include the safety pin and removable cap, both of which need to be taken off (as you can see in the B-roll of training video).

The firing sequence and performance of this round, in all but terminal effect, apes the more common PG-7 or PG-7V warhead, the twin-conical HEAT warhead. The booster charge (section III in the cutaway PG-7V image below) expels the OG-7 from the tube at 117 m/sec (384 fps) in a tenth of a second, by which time it has traveled 11 meters (~36 feet). The booster charge is routed through a de Laval nozzle or venturi that equalizes the pressure of the gases exiting the rear of the tube with the recoil from the grenade being expelled from the front — making, in an in-spec RPG, the recoil functionally zero. At the 11-meter point the rocket sustainer (II in the cutaway) fires and propels the warhead section, hitting a peak velocity of 294 m/sec (965 fps) until it hits the target, or if it finds no target or other object or surface, until 5 seconds have elapsed. At 5 seconds, the round is 900 meters (~2950 feet) from launch, and it self-destructs.

The round is stabilized by spring-out fins hinged inside Section III (the fins are shown stowed as 17). These fins are also beveled on one side of their leading edges to provide stabilizing spin in addition to the aerodynamic stability the fins supply. In addition, a small group of secondary fins (19) provides spin even during the in-tube boost.

Here is B-Roll of an interview with one of the Marines, Sgt. Christopher Samples.He explains what the training meant to achieve, and the roles of the gunner and a/gunner in an RPG crew. “It’s commonly used, but it’s commonly misused, as well. Once they learn how to effectively use it, it can be used against the enemy.”

In this interview, ammo tech Corporal Ryan McCarthy explains how the RPG works, according to his own understanding, and what he’s looking for: “Safety. Safety, safety, safety!”

And here is the finished, journalistic product, blending excerpts from the two interviews and the range fire on 24 August 11.

The RPG is a really, really outstanding weapon, and it fits in a sweet spot of direct-fire AT and AP support weaponry that’s really missing in the US infantry squad. Instead, we have more riflemen, and additional-duty weapons like the AT-4. The RPG is cheaper and reusable, and it has a range advantage over most US disposable non-guided weapons. Its effective anti-tank range is about double that of the AT-4, and the disposable AT-4 costs $1,500 a round.

History of the Weapon

The evolutionary history of the RPG is fascinating. The Soviets began by copying a weapon they’d felt the sharp end of: the German Panzerfaust. There were many versions of this disposable AT weapon available, and by war’s end the Germans were evolving this weapon in the direction of a reusable tube. It was the Panzerfaust that originated the grenade-launch boost and rocket sustainer operating system, and the weapon evolved rapidly under the pressures of mechanized warfare. Early Panzerfäuste had a mere 30 meter range, demanding bravery, or recklessness, from a rifleman under the pressure of hordes of T-34s or Shermans. And the warheads were marginal, at least on the well-protected T-34. By 1945 most of the initial weaknesses had been allayed by the intense development taking place behind the lines, and the industrial and R&D plant fell into Russian hands.

Unlike the USA, where captured German scientists and engineers came to be trusted, with many staying on as employees and seeking American citizenship, the Soviets, who suffered terribly at German hands, never trusted the Germans and held them in rigid captivity. As quickly as possible, they transitioned German projects, including rockets, guided AA missiles, and turbine engines as well as AT weapons, to Soviet design bureaux and shut the Germans out, generally releasing them back in the USSR’s occupied zone of Germany.

The Soviet engineers proved to be quick and imaginative. They continued to improve the Panzerfaust operating system. It is generally believed that a Soviet-produced version of the late-war Panzerfaust 250 was given limited issue as the Ручной Противотанковый Гранатомёт Ruchnoy Protitankovniy Granatomet or RPG-1. A Soviet-improved version was widely issued as the RPG-2 in the later 1940s, as part of the systematic re-equipment of the Soviet Army that also saw new rifles, machine guns, and soon, tanks in service.

The limits of the RPG-2 led to the larger, heavier, more solid, and tactically longer-ranged and more accurate RPG-7 in 1961, and the versatility of the RPG-7 has kept it on the world’s front lines to this day. While most of the world knows about the remarkable longevity of the Kalashnikov rifle, its AT counterpart is just as ubiquitous, and won’t be going away any time soon. (In fact, a US firm makes a modified version for Foreign Military Sales).

The RPG has come a long way from its origins as a copy of a last-ditch throwaway weapon of the Nazi empire. Indeed, it has outlived the other empire that bore it, and stands like a monument to good incremental/iterative design. Weapons themselves have no ideology; they’re just tools, and can be used for good or for ill. This one endures because the RPG-7 version is a superior design that fits a unique tactical niche.

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