5.45×39mm

Lore & Background

The 5.45×39 mm cartridge was developed in the early 1970s by a group of Soviet designers and engineers under the direction of M. Sabelnikov. It couples a sensible case volume to bore area ratio with ample space for loading relatively long slender projectiles that provide good aerodynamic efficiency and external ballistic performance. The original military issue 7N6 cartridge variant introduced in 1974 is loaded with full metal jacket bullets that have a complex construction, including a steel rod penetrator core, a lead inlay, and a hollow cavity inside the nose, which contributes to tumbling upon impact.

During the Soviet-Afghan War, the 7N6 ball round became known among Afghan mujahideen as the 'poison bullet' because it caused more damage to internal tissue and organs compared to the 7.62×39 mm round, leading to infections and gangrene due to delayed treatment and antibiotic shortages. In the Russo-Ukrainian War, Ukrainian forces used predominantly 5.45×39 mm ammunition, citing unorganized donations of rifles, lack of 5.56×45 mm NATO ammunition, and the wide availability of weapons and ammunition from the Soviet era, as well as the ability to resupply from Russian positions.

Military 5.45×39 mm ammunition was produced in the former Soviet Union, the GDR, Bulgaria, Poland, and Romania. In the former Soviet Union, production occurred in Russia, Ukraine, Kazakhstan, and possibly other republics. Ukraine did not resume production in 2024 after the Russian takeover of the Luhansk Cartridge Plant in 2014, and Kazakhstan plans to begin mass production in 2024.

Reader's Guide

The 5.45×39 mm cartridge represents a key shift in military small arms ammunition, reflecting an international tendency toward smaller, lighter, high-velocity cartridges that allow soldiers to carry more ammunition for the same weight. Its introduction with the AK-74 marked the Soviet response to the American 5.56×45 mm NATO, and it became the standard service cartridge for the Soviet Union and Warsaw Pact. The cartridge's design, particularly the 7N6 bullet with its hollow cavity and steel penetrator, produced distinctive wounding effects that led to the 'poison bullet' myth during the Soviet-Afghan War. Ballistics tests showed a pronounced tumbling effect, though later studies indicated it acts as expected of full-metal-cased ammunition without expansion or fragmentation in soft tissues. The cartridge's penetration capabilities against body armor at longer ranges were questioned, leading to enhanced penetration variants such as the 7N6M, 7N10, 7N22, 7N24, and 7N39. Its continued use in the Russo-Ukrainian War highlights its enduring relevance, with both Ukrainian and Russian forces relying on it due to historical availability and logistical factors.

Did You Know?

• The 5.45×39 mm cartridge was developed in the early 1970s by a group of Soviet designers under M. Sabelnikov.
• The original 7N6 bullet has a hollow cavity in the nose and a steel rod penetrator, contributing to tumbling on impact.
• During the Soviet-Afghan War, the round was called the 'poison bullet' by mujahideen due to severe wound infections.
• Ukraine did not resume production of 5.45×39 mm ammunition in 2024 after the Russian takeover of the Luhansk Cartridge Plant in 2014.

Engineering a Lighter, Flatter Round

The 5.45×39mm emerged from an early-1970s Soviet design effort led by M. Sabelnikov alongside eight other engineers, including L. I. Bulavsky, B. B. Semin, and P. S. Korolev. Their goal was to produce a rimless, bottlenecked intermediate cartridge that could rival the American 5.56×45mm NATO in delivering a light, flat-shooting projectile. The designers paired a modest 1.75-millilitre case with a bore area of roughly 24 square millimetres, a ratio that left generous internal volume for long, slender bullets with strong aerodynamic profiles. This approach reflected a broader global shift: soldiers could carry more rounds for the same weight, enjoy a favourable battle-zero range, and benefit from reduced bolt thrust and free recoil—qualities that favour lightweight rifles and sustained automatic fire. The original 7N6 round, introduced in 1974, weighed just 10.75 grams, and the AK-74's free recoil energy measured only 3.39 joules, well below the 6.44 joules of the M16 or the 7.19 joules of the AKM.

The 'Poison Bullet' of Afghanistan

When the AK-74 entered the Soviet-Afghan War, its 7N6 ball round earned a fearsome nickname among Afghan mujahideen: the "poison bullet." The round's unusual internal construction—specifically the hollow air cavity at the nose, created because the thin lead inlay did not fill the entire point end—made the projectile's tip deform on impact with solid objects. Combined with a small lead plug crimped into the base, this shifted the bullet's centre of gravity rearward, inducing pronounced yaw and tumbling once it struck tissue. High-speed camera tests confirmed this dramatic destabilisation. In the field, the resulting cavitation and internal damage proved far more devastating to organs than the older 7.62×39mm round. Wounded fighters, often left without medical care for days in a setting starved of antibiotics, rapidly developed gangrene and fatal infections. The mujahideen, unable to explain the severity of the wounds, concluded the Soviets were firing chemically poisoned ammunition—a belief born entirely of the bullet's mechanical design.

A Cartridge Across Borders

The 5.45×39mm was never confined to a single nation's arsenals. After its 1974 introduction, it progressively supplanted the 7.62×39mm as the standard rifle round across the Soviet Union and its Warsaw Pact allies. Production spread widely: Russia, Armenia, and Azerbaijan manufactured it within the former Soviet space, while East Germany, Bulgaria, Poland, and Romania all ran production lines. Ukraine had been a significant producer until Russian forces seized the Luhansk Cartridge Plant in 2014, though Kyiv managed to restart 5.45×39mm output by 2024 and simultaneously began manufacturing 5.56×45mm NATO ammunition. Kazakhstan also announced plans to enter small-arms cartridge production, with 5.45×39mm among the expected types and mass production targeted for 2024. On the technical side, C.I.P. standards set the cartridge's maximum piezo pressure at 355 megapascals, and in regulated markets every chambered weapon must be proof-tested at 125 percent of that figure—roughly 444 megapascals—before it can reach consumers.

Resupply by Necessity: The 2024 Ukrainian Front

By April 2024, a striking paradox defined the Ukrainian battlefield: despite years of Western aid, Ukrainian troops were firing predominantly 5.45×39mm ammunition. Jonathan Poquette, an American national serving in the Chosen Company attached to the 59th Motorized Brigade, offered a pragmatic explanation. First, donations of 5.56×45mm NATO rifles had arrived in an uncoordinated fashion—some units received them, others did not. Second, the flow of NATO-standard ammunition from Western donors had been inconsistent and insufficient. Third, and perhaps most decisively, Ukraine's decades as a Soviet republic meant that 5.45×39mm-capable weapons were already deeply embedded in its inventory. Finally, the enemy's logistics created a practical resupply channel: Russian forces standardised on the same cartridge, so an attacking unit pressing into a Russian position could simply collect usable 5.45×39mm rounds from the fallen.