Ordnance Notes -- by Bob Stoner GMCM (SW) Ret.
Heckler and Koch Gewehr 3 (G3) 7.62mm Rifle
One of the more common 7.62mm NATO main battle rifles is the H&K G3-series. The G3 has been produced in numerous countries and has served or serves with many armies, special operations forces, and police organizations. The story of the G3 goes back to World War 2.
The Germans were the first to introduce the world to the Sturm Gewehr (StG) or assault rifle concept. They fielded numerous guns in their 7.92x33mm (7.92mm kurz or short) caliber. The most common were the MP43 and MP44 series of rifles. At the time the war ended in Europe, Dr. Ludwig Vorgrimmler and some other technicians at Mauser were working on the StG45 which employed a radically different locking system than that used by the MP43 and MP44. Dr. Vorgrimmler and some of his technicians left Germany for Spain to continue development of the StG45.
The Spaniards were looking for a modern replacement for their bolt-action Mauser rifles. However, they wanted a rifle with more range than the 7.92x33mm cartridge offered. In 1948 the Special Materials Technical Studies Center (CETME) was established to pursue development of the rifle and cartridge. By 1949 a prototype rifle was produced and by 1952 the new CETME rifle was being demonstrated in Spain and Germany.
While the Spaniards were working on the CETME, the Germans were trying to rebuild their country after its devastation in World War 2. In 1949 the North Atlantic Treaty Organization (NATO) was created and a new German armed forces (Bundeswehr) was reborn. The Bundeswehr was originally equipped with ex-American weapons, but the Germans wanted a new rifle with advanced capabilities. The Germans contracted for a new rifle, the Gewehr 1 (G1) with the Belgian firm of Fabrique Nationale in Liege, Belgium. FN delivered 100,000 G1 rifles to Germany to arm the Bundeswehr, but negotiations for a licensing agreement to produce the rifle in Germany fell through. In 1957 both Germany and Spain adopted the CETME; in Germany the rifle was known as the Gewehr 3 (G3) and in Spain as the CETME. Getting the rifle into production resulted in the first of a series of Spanish-German joint-development accords between Heckler and Koch and CETME.
At first, the rifle was produced in two calibers: the 7.62mm NATO for Germany and the 7.62mm CETME. The later Spanish cartridge was identical in size and shape to the German round, except for a reduced powder charge. Both German and Spanish guns were marked with the CETME logo until 1961, when it was dropped from the German gun. In 1964 the Spaniards standardized their CETME Model C rifles to fire the 7.62mm NATO cartridge. The G3 and CETME rifles are quite similar in appearance but there are subtle differences in construction and finish between them. Most striking is the German use of plastics for the butt stock, pistol grip and forearm; the Spanish preferred to use the more traditional wood. German guns have a black epoxy finish, while Spanish guns have a Parkerized (manganese phosphate) finish. Both countries developed several versions of the G3 and CETME in various calibers. H&K in Germany really pushed the concept of the roller-locked breech for various guns. It designed whole families of weapons in various calibers using the roller-locked breech concept that have been marketed world wide.
The weapon chosen by Navy SEALs for operations in Viet Nam was the German-produced G3A3. The G3 is unique among the weapons standardized by NATO during the 1950s as having the roller-locked breech mechanism and fluted chamber. The receiver of the G3 is a stamping. The barrel is pinned into a trunnion block (containing the locking recesses for the bolt rollers) and the trunnion is pinned and welded into the receiver stamping. The bolt of the G3 is composed of two parts: the bolt head which contains the bolt locking rollers and the bolt carrier which contains the firing pin and locking cam. The cocking lever for the G3 is housed in a tube above the barrel. The cocking lever is located on the left side of the tube near the front sight. When the cocking lever is extended, the bolt carrier is moved back to release the bolt rollers (this requires some effort) before the lever can be pulled fully to the rear to load or clear the rifle.
Operation: when the bolt chambers a cartridge, the bolt head (with locking rollers retracted) enters the trunnion block. The following bolt carrier closes and the locking cam extends the bolt rollers into their locking recesses in the trunnion block. When the firing pin fires the cartridge, the rollers hold the bolt locked in the trunnion block until the pressure drops to acceptable levels. The G3 uses a fluted chamber to float the cartridge case on propellant gases to prevent the case from sticking to the sides of the chamber. Once the pressure drops to a safe level, the bolt carrier moves back, the locking cam retracts, and the bolt rollers move into the bolt head (unlock). Extraction and ejection of the fired case from a G3 is very positive and violent. Fired cases will typically show blackened, longitudinal scorch marks around the diameter of the case and a dent where the case has hit the edge of the ejection port. The G3 is a select fire rifle and is very simple to maintain in the field. The rifle is easily fitted with a quick-detachable telescopic sight or night vision devices for special missions.
and Koch G3A3 Specifications:
© 2005 Bob Stoner R3