In the annals of military small arms development, few stories are as laden with technical challenges, political intrigue, and ultimately, a tale of standardization as the NATO Personal Defense Weapon (PDW) trials. The trials, which began in earnest in the late 1990s, aimed to arm support personnel with a weapon that was more compact and powerful than a pistol but more manageable than a full-size rifle.
At the heart of the PDW concept was not just the weapon itself but the cartridge it fired. The trials sought to replace the long-standing 9mm NATO cartridge with a new round capable of penetrating modern body armor. The result saw two cartridges, the 5.7x28mm developed by FN Herstal and the 4.6x30mm developed by Heckler & Koch, emerging as top contenders. Despite the promising start, the trials were not without their setbacks.
The political landscape of NATO member nations played a pivotal role in the adoption of a new PDW caliber. The NAAG report from 2002 offers a glimpse into the trials’ complexities, revealing that the French and Belgians pushed for the 5.7x28mm cartridge to replace the 9mm. They saw it as a progressive step in phasing out the older round and had even begun drafting a new standardized agreement (STANAG). However, the process was disrupted when Germany introduced their 4.6x30mm cartridge.
Despite the clear intention to find a more capable replacement for the 9mm, the new cartridges did not fulfill the original ambition of penetrating Russian paratrooper armor—an objective often cited but never the program’s true intent. Instead, they were designed to phase out the 9mm and offer a different approach to dealing with body armor. The new PDW calibers were tested against CRISAT armor, which consists of 1.5mm titanium plates and Kevlar, to gauge effectiveness against what could be considered a minimum standard for body armor penetration.
The technical trials and the ensuing political impasse led to a significant delay in standardization. It wasn’t until 2020, nearly two decades after the initial comparative tests, that both 5.7x28mm and 4.6x30mm calibers were standardized under STANAG 4509. This decision showcased a compromise, acknowledging that no single cartridge could be chosen over the other.
Interestingly, the NATO trials had an unintended consequence. They spurred the development of new weapons and cartridges, such as Russia’s PP2000 and the 7N31 9mm AP cartridge. This development reflected a universal pursuit among armed forces for a cartridge that could defeat body armor while maintaining compatibility with existing platforms.
The trials underscored the importance of consensus in NATO’s decision-making process. The inability to reach an agreement on a single PDW caliber highlighted the influence of national interests on military standardization. Despite the challenges, both the FN P90 and HK MP7 found their niches within special operations and law enforcement units around the globe.
This saga of the NATO PDW trials and the eventual standardization of both the 5.7x28mm and 4.6x30mm cartridges reflects a complex interplay of technological, political, and strategic considerations. The adoption of these cartridges, while not replacing the 9mm as once envisioned, has nonetheless expanded the capabilities of NATO forces, paving the way for future advancements in small arms technology.
Relevant articles:
– NATO PDW trials: the forbidden saga of “MP7 vs P90” 9holereviews.com, Nov 5, 2021
– How NATO killed the Personal Defense Weapon concept Sandboxx, Oct 14, 2022
– PDW Round Comparison 5.7x28mm vs 4.6x30mm The Ballistic Assistant, Nov 25, 2021
– Modern Personal Defense Weapon Calibers 002: The 4.6x30mm HK – The Firearm Blog, Oct 24, 2016