Improving the combat effectiveness of rifle and machine gun ammunition in the light of recent combat experience was a strong theme at IQPC’s Infantry Weapons conference, which took place from the 20th to the 22nd of September in London. Doubts about the effectiveness of the 5.56x45mm NATO round have led to widespread re-issue of 7.62x51mm weapons for longer range engagements, increased use of combat shotguns for close quarter battle and a resurgence of interest in an intermediate calibre such as 6.8x43mm or 6.5x38mm as well as efforts to beef up existing rounds.
Delegates were brought up to date on the U.S. Army’s efforts to improve the 5.56x45mm M855 ammunition through the M855 A1 Enhanced Performance Round (EPR) programme. Lieutenant Colonel Jeffrey K Woods, U.S. Army product manager for small and medium calibre ammunition at the Manoeuvre Ammunition Systems (MAS) organisation based at Picatinny Arsenal, outlined the aims and achievements of the EPR programme. Advocating a different approach was independent ammunition consultant Anthony G. Williams who called for the replacement of both the 5.56 and 7.62mm NATO rounds with something of intermediate calibre. Author and consultant William F. Owen contributed to the debate with a case against investing large amounts of money in new ammunition and weapons to fire it when the source of the effectiveness problem, he argues, might well lie in training and doctrine.
While this debate is far from a new one, it is particularly relevant now after nearly a decade of combat in Southwest Asia that has brought infantry small arms to the fore. Recent and ongoing combat operations continue to highlight the strengths and weaknesses of current western inventories, expanding them with a variety of extra firearms, and exposing the guns to wear and tear at the highest rate for many years. These factors will inform the procurement decisions of leading armed forces planning to replace large numbers of infantry weapons over the next decade. Because the round of ammunition is the heart of the infantry soldier’s weapon system, its effectiveness is critical.
M855A1 Enhanced Performance Round
U.S. warfighters in Afghanistan are now being issued with the new M855A1 EPR for assault rifles, particularly the M4 carbine and M16 rifle, but there is still some testing to be conducted, said Lt Col Woods, before it is approved for the M249 Squad Automatic Weapon (SAW) light machine gun. When asked, Lt Col Woods stressed that EPR is not more lethal than the M855, just more consistently so in a much wider range of conditions. The new round is designed to achieve more consistent effects on soft targets, improve effectiveness after penetration of intermediate barriers such as car doors, and retain this improved performance at longer range than the M855.
The new round develops higher chamber pressure and higher velocity than the M855 and there are differences in the design of the projectile, which features a steel penetrator at the tip ahead of the copper jacket around the copper core.
This work has borne fruit, he says, in that it is now superior in performance to the M855 and even the 7.62mm M80 round on soft targets. While the M855 bullet depends on either yaw or fragmentation inside the target for maximum transfer of kinetic energy, the EPR does not, said Lt Col Woods, but neither is it designed to expand since that would be against the laws of war. Instead, the EPR reacts consistently each time, regardless of angle of yaw.
Against hard targets, the M855 A1 is clearly superior to the M855 even judging by the fairly approximate figures that Lt Col Woods presented. Fired from an M4 carbine, the M855 will penetrate a 3/8-inch steel “battle barrier surrogate” from a range of about 150 m, but the EPR will do so in excess of 350 m. And whereas the M855 will not penetrate a concrete masonry unit, the EPR will get through such a barrier from a few tens of metres. Fired from the longer barrelled M16, the results are even better with the EPR penetrating the steel barrier at almost 400 m and the concrete masonry unit at comfortably more than 80 m. The EPR’s penetration of the 3/8-inch steel barrier is significantly better than that of the 7.62mm M80, and it will also penetrate some types of lower quality body armour. The M855 also performs better from the longer barrelled weapon, although it still won’t penetrate the concrete barrier.
The EPR is also said to be slightly more accurate than the M855, but its ballistics are so close, says Lt Col Woods, that soldiers are not required to re-zero their weapons, although there is some benefit in doing so. Soldiers have noticed that it is possible to spin the tip of some bullets, but this is not a fault, he insists, just a characteristic. “If anything, I’ve seen these rounds fire slightly more accurately.” The small gap noticeable between the tip and the edge of the jacket is also quite normal.
Ammunition costing less than .10 cents per round above the M855’s cost was the goal and the team has exceeded that comfortably, bringing the long term cost to within five cents per round. PM MAS is now looking to apply the same technology to 7.62mm ammunition.
The M855 A1 EPR is only issued to U.S. troops at the moment, but is likely to be made available for export to military customers through the usual channels.
Limitations of Today’s NATO Rounds
While the EPR programme seeks to get the best from the existing 5.56x45mm round, Anthony G. Williams called for a much more fundamental rethink at a time when many NATO armies are starting to consider what should replace aging families of 5.56mm firearms. In his presentation entitled Biting the Bullet – the Case for Adopting a Medium Calibre Cartridge, Anthony Williams acknowledges other detailed critiques of U.S. and NATO small arms ammunition policy, notably those by Gary K. Roberts and Thomas P. Ehrhart, and broadly shares their conclusions. Gary K. Roberts is a Lieutenant Commander in the U.S. naval reserve who wrote Time for a Change – U.S. Military Small Arms Ammunition Failures and Solutions, while Thomas P. Ehrhart is a U.S. Army major who wrote Increasing Small Arms Lethality in Afghanistan: Taking Back in the Infantry Half Kilometre. All conclude that an intermediate calibre larger than the 5.56x45mm but smaller than the 7.62x51mm should be procured to replace the former and, Williams argues, the latter also. The round that all recommend would have a calibre of between 6.5 and 7 millimetres and overall dimensions about the same as those of the 5.56x45mm. Although Anthony Williams’ critique and the other works to which he refers draw on UK and U.S. experience in combat since 2002, the issues also clearly affect other NATO allies. He wrote his paper in cooperation with Nicholas Drummond, an independent strategy consultant and former infantry officer.
Williams stresses that combat conditions in Afghanistan emphasise the performance of infantry and their weapons because most engagements require precise targeting with limited effects and the ability to limit collateral damage. He argues that the ranges at which current doctrine assumes most infantry engagements will take place are too short. Specifically, the idea that 75 percent of engagements would be within 200 m, 90 percent within 300 m and 100 percent within 500 m is not borne out by experience in Afghanistan. This has shown that 25 percent of engagements happen within 200 m or so, 50 percent within about 300 m, 75 percent within about 450 m and 100 percent within 900 m.
This creates obvious problems for Western soldiers engaged by insurgents using weapons such as the PKM light machine gun and the SVD semiautomatic sniper rifle that are chambered for the old but powerful Russian 7.62x54R round. British soldiers, for example, use a family of 5.56mm weapons of which none has an effective range greater than about 400 m, a range that varies with barrel length. For example, the standard infantry rifle is the L85A2 version of the SA80 that has a 20-inch barrel and is effective out to around 300 m, considerably out ranging the 14-inch barrelled L110A1 LMG (the UK version of the FN Minimi), which is said to be effective out to around 200 m. The 5.56mm weapon with the longest reach in the British infantry squad is the L86A2 Light Support Weapon, a 25-inch barrelled LMG variant of the SA80 that is effective out to around 400 m.
Williams argues that this means that more than 50 percent of engagements are beyond effective rifle range, a proportion that grows to 70 percent with short-barrelled weapons. Coupled with inadequate suppressive effect suggested by reports of Taliban ignoring 5.56mm fire at longer ranges, unreliable terminal performance due to erratic yaw characteristics, and an inability to penetrate intermediate barriers, this puts British troops at a severe disadvantage in long-range engagements, argues Williams.
The propensity to yaw after impact is so important for a military bullet because yawing is the primary legally sanctioned means of maximising its delivery of energy to the target, which is critical to its ability to incapacitate an adversary quickly. When a bullet yaws after impact, it will be travelling sideways for a portion of its journey into the body, presenting a greater surface area and creating a larger wound channel. If the bullet fails to yaw, it will only create a small wound channel and cannot be relied upon to stop a determined enemy. There is a growing body of evidence that this happens to a number of NATO 5.56 millimetre bullets including that of the U.S. M855 at all ranges. The 1899 Hague Convention outlaws the military employment of bullets that use alternative mechanisms such as controlled expansion to maximise terminal effect, even though this type of ammunition has been routinely used by law enforcement organisations the world over for many decades.
It is these problems that have led to the resurgence in interest in and employment of rifles and machine guns chambered for longer ranged and harder hitting 7.62x51mm ammunition, argues Williams. He cites as examples the U.S. re-adoption of the old M14 in updated Enhanced Battle Rifle (EBR) guise and of the Mk48 LMG, along with the British Army’s reallocation of the GPMG to foot patrols and the procurement of the L129A1 designated marksman rifle as an Urgent Operational Requirement (UOR). This trend is so strong that most major manufacturers of military firearms now offer 7.62mm versions of their most modern assault rifles. And re-chambered versions of machine guns originally designed for the smaller round are increasingly in evidence.