5.56mm
The 5.56mm cartridge is a small-caliber, high-velocity round commonly used in military and civilian rifles, particularly in AR-15-style firearms. Developed in the 1960s, it became the standard for NATO forces due to its balance of range, accuracy, and low recoil, making it suitable for automatic and semi-automatic fire. The 5.56mm is lighter than larger calibers, allowing soldiers to carry more ammunition. Known for its high velocity, it is effective at penetrating soft body armor but loses effectiveness at long distances compared to larger rounds like the 7.62x39mm.
| Factions | Weapon | Icon | Classes | Ammo | Damage | |
|---|---|---|---|---|---|---|
| Normal | Headshot | |||||
 US |
 M16 XM148 |
 |
 Assault |
20+1 / 60 1 / 2 |
37 | 92 |
US |
 M16A1 |
 |
Assault |
20+1 / 60 | 37 | 92 |
US |
 M16A1 M203 |
 |
Assault |
20+1 / 60 1 / 2 |
37 | 92 |
US |
 M16A1 SOG |
|
WIP | 20+1 / 60 | 37 | 92 |
US |
 M601 |
 |
Assault |
20+1 / 60 | 37 | 92 |
US |
 M605B |
 |
Assault |
20+1 / 90 | 37 | 92 |
US |
 M656 |
 |
 Sniper |
20+1 / 40 | 37 | 92 |
US |
 Mk4 Mod 0 |
 |
Assault |
20+1 / 60 | 35 | 87 |
US |
 Stoner 63A Rifle |
 |
Assault |
30+1 / 90 | 33 | 82 |
US |
 Stoner 63A Carbine |
 |
Assault Radioman |
30+1 / 90 | 33 | 82 |
US |
 Stoner 63A Commando |
 |
 Gunner |
150 / 300 | 33 | 82 |
US |
 Stoner 63A Bren |
 |
Gunner |
30 / 90 | 33 | 82 |
US |
 Stoner 63A LMG |
 |
Gunner |
100 / 200 | 33 | 82 |
US |
 XM177E2 |
 |
Assault Radioman |
30+1 / 90 | 35 | 87 |
US |
 XM177E2 4x |
 |
Assault |
20+1 / 60 | 35 | 87 |
US |
 XM177E2 OEG |
 |
Assault |
20+1 / 90 | 35 | 87 |
US |
 XM177E2 SOG |
 |
Assault Radioman |
30+1 / 90 | 35 | 87 |
US |
 XM607 |
 |
Assault Radioman |
30+1 / 90 | 35 | 87 |
US |
 XM607 4x |
 |
Assault |
20+1 / 60 | 35 | 87 |
US |
 XM607 OEG |
 |
Assault |
20+1 / 90 | 35 | 87 |
HISTORY
The 5.56×45mm NATO round has its roots in the post-World War II era, a period when military strategists were rethinking small arms for infantry. The experiences of World War II showed that high-power rifle cartridges, such as the American .30-06 Springfield and the German 7.92×57mm Mauser, were powerful and effective at long range but often more than what was needed for typical combat distances. Soldiers often engaged in battles at less than 300 meters, making the heavy recoil and weight of these rounds more of a drawback than an advantage in many situations.
As the Cold War intensified, the Soviet Union introduced the 7.62×39mm round along with the AK-47, which was lighter and had less recoil than traditional rifle cartridges, making it more suitable for close-quarters combat and for use by a broader range of soldiers. This influenced NATO to consider lighter, smaller-caliber rounds that could achieve similar results in terms of controllability and portability while still providing effective stopping power.
The United States military became interested in a lighter cartridge that could allow soldiers to carry more ammunition, offer manageable recoil, and maintain accuracy over typical combat ranges. In the late 1950s, Eugene Stoner and the Fairchild Armalite Corporation designed the AR-15 rifle chambered for the .223 Remington, a .22-caliber round designed to meet these criteria. The U.S. military saw potential in this combination, and the .223 Remington was soon refined and adopted as the 5.56×45mm cartridge when the AR-15 was modified and designated as the M16 rifle.
With the introduction of the M16 in the 1960s, the 5.56×45mm round became widely used in Vietnam, where it proved effective in close-range jungle warfare. The lighter recoil and higher magazine capacity allowed soldiers to engage in sustained fire more easily than with previous rifles. However, there were initial issues with reliability and performance due to mismatches between the M16’s design and the conditions in Vietnam, as well as early problems with ammunition and maintenance instructions. Over time, refinements to both the rifle and the cartridge led to increased reliability, and the 5.56mm round became a mainstay of the U.S. military arsenal.
In 1980, NATO formally adopted the 5.56×45mm round as its standard intermediate cartridge. This standardization across NATO countries enabled interoperability among allied forces, and the round became widely used in militaries around the world. NATO also developed the SS109 variant, known as the M855 in the U.S., which featured a steel penetrator to increase its effectiveness against light armor, giving it better penetration capabilities than the original M193 round used in the Vietnam War.
Today, the 5.56×45mm NATO remains one of the most widely used rifle cartridges in the world, with its lightweight, low-recoil, and effective range continuing to make it suitable for modern infantry weapons. However, advancements in body armor and changing combat conditions have led some militaries, including the U.S., to explore new calibers that may one day replace or complement the 5.56mm, potentially bringing the round’s dominance to a close.
SOURCE