Let’s take a look at them. So in the late 1950s, the US Department of Defense’s Project Salvo studies suggested that a small high velocity caliber could be more effective. Shortly afterward, Remington Arms independently developed the 223 Remington cartridge. After several years of testing, the US military decided to adopt it and standardize it as the 5.
56x 45mm NATO, which would later become the primary caliber for assault rifles. The new cartridge had gained many advantages. Its grouping and rate of fire increased while recoil, muzzle rise, and ammunition weight decreased. However, in the war in Afghanistan, special forces preferred the old 7.62 over the 5.56.
Regular soldiers, on the other hand, could not choose. But what advantages did the older caliber have? Firstly, the 7.62 62 NATO round travels more steadily than the 5.56 round. Factors such as wind, rain, or snow affect the trajectory of the 5.56 far more than that of the 7.62. Secondly, the 7.
62 has fewer ricochets than the 5.56. In addition, a heavy 7.62 bullet fired from an M14 or an M240 at extreme distances loses much less energy than a 5.56. Yes, the weight of the 5.56 round is lower. It weighs approximately 12 g compared to the 24 g of the 7.62. But at the same time, the 7.62 is capable of better retaining its lethality throughout its entire trajectory.
It should also be noted that during the war in Afghanistan, there were many types of 7.62 62x 51 mm NATO rounds and special forces could choose the right type for a specific task from standard ammunition to armor-piercing or precision sniper rounds. Meanwhile, for example, subsonic 5.56x 45 mm NATO rounds for use with silencers were uncommon, and the armor-piercing rounds never reached the effectiveness of the 7.
62 against armor or fortified positions. The problem was not only the variety of ammunition, but also of tactical accessories. For the 7.62x 51 caliber, suppressors had long existed and been tested in various operations used, for example, on rifles like the G3 or the modernized versions of the M14. By contrast, weapons using the 5.56×45 round had more difficulty being truly silenced.
The high velocity, low impulse round is harder to suppress, and using a suppressor considerably reduces its combat performance. The 5.56 mm kills through high velocity fragmentation and cavitation. And with a suppressor, its velocity drops, it may not fragment, and it becomes much less lethal. Moreover, the 7.62 had a greater effective range.
