By Chris Upchurch, Director of Marketing
The G3 battle rifle is the progenitor of HK’s family of roller delayed blowback firearms. From humble origins it has risen to become one of the most widely used battle rifles in the world and spawned an incredible variety of derivatives and descendants.
The G3’s roller delayed blowback design traces its roots back to the MG42 machinegun of World War II. The MG42 was a recoil operated design that used a roller system to keep the bold locked to the barrel until pressure dropped enough to be safely opened. During the final years of the war, Mauser engineers were working on a new assault rifle as a successor to the StG44. They began with the MG42’s action and attempted to adapt it to gas piston operation (a recoiling barrel was considered undesirable in an assault rifle). They found that with the correct design of the roller system, the gas piston was unnecessary.
The war ended before the new assault rifle, the StG45(M), could be produced in any numbers. Some of the engineers working on the design were relocated to France after the war, where they worked on an assault rifle design that went through several potential chambering before finally settling on the U.S. .30 Carbine round. The CEAM Modéle 1950 was scrapped in part due to the financial demands of France’s war in Indochina (the first of many new weapon designs that lost out to the war in Vietnam).
The CETME modelo A
One of the designers, Dr. Ludwig Vorgrimler, moved to Spain, where he created the CETME rifle. As with the French design, this rifle went through several chamberings, including 7.92x33mm Kurz, 7.92x40mm CETME, and 7.62x51mm CETME (dimensionally identical to, but less powerful than the 7.62x51mm NATO round). Spain, not being involved in a war in Southeast Asia, adopted the CETME rifle as their standard service weapon.
When the German armed forces were reformed after WWII as the Bundeswehr, they initially wanted to adopt the FN-FAL (at the time used by many other NATO members) as their standard service rifle, but the Belgians refused to license it for production in Germany. Instead they evaluated the SIG SG 510, Armalite AR10, and CETME. CETME won the contract and after it was adapted to fire the full power 7.62x51mm NATO cartridge it entered production as the G3.
While today the G3 is closely associated with HK, up until 1969 production was split between HK and Rheinmetall. Nevertheless, HK were the ones to help redesign the rifle to take the full power 7.62x51mm NATO round, and to carry roller delayed blowback the design forward into submachine guns (MP5), machine guns (HK21), other rifle calibers (HK33) and even pistols (P9).
In addition to the standard battle rifle, HK also produced the G3KA4, a carbine model with a 12.4 inch barrel. Another notable variant is the G3SG/1, an sniper variant with a cheek rest and enhanced trigger group.
The G3 was also the father of a large variety of HK firearms. Closest to the G3 in design are the PSG1 and MSG90 sniper rifles. The G3 was essentially scaled down to produce the 5.56mm HK33 assault rifle, as well as the MP5 submachinegun. While there are more differences, the G3 also lent many features to the HK21 and HK23 family of machineguns. The roller delayed blowback system even made its way into HK’s P9 pistols.
The G3 design has been widely adopted, seeing service with over 50 armies, particularly in Latin America and Africa. Germany encouraged other countries to adopt the G3 in part by being very willing to license production and sell tooling to make the guns. Starting with Portugal in the 1960s, the G3 was eventually produced in more than a dozen countries. Tooling from the plant in Portugal was eventually brought to the U.S. and is now used to make the PTR–91.
The U.S. Army’s Aberdeen Proving Ground evaluated the G3 and its 5.56mm little brother, the HK33 in 1969. The results were favorable and they concluded, “Compared to other automatic weapons, the variation that can be tolerated in the cycling of these weapons is extremely large. These weapons should continue to fire under adverse environmental conditions and with large variations in the ballistic performance of ammunition.”
The G3 saw service even with nations that had their own battle rifles. The British SAS and SBS adopted the G3 as their 7.62mm rifle and used it extensively in Northern Ireland. They made use of the short barreled G3KA3 versions for vehicular use, and even had their own 9" barreled version called the MC51.
Thanks in part to its relatively simple stamped construction the G3 remained in production for military use longer than its 7.62x51mm rivals, the FAL and M–14. It remains in service with many countries, either as the standard service rifle or in niche roles like a designated marksman’s rifle.
The G3 has a long and distinguished history of service. It has probably spawned a bigger and more varied family of related firearms than any other rifle, including the AK. Truly one of the classic fighting rifle designs.
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