Workhorse rifle 'failing US troops in Afghanistan'

The US military thinks it may have got one of the basics wrong: its guns are not good enough. A US Army study found that the M-4 rifle, the workhorse weapon of America's troops, is ineffective at ranges of more then 300m because bullets lose the velocity necessary to kill an enemy.

Although the dense vegetation and warrens of mud-packed houses in parts of southern Afghanistan lend themselves to close-range fighting, there are also many battles where Taliban fighters make use of the heavier calibre of their AK-47s to ambush Nato and Afghan soldiers from afar.

The AK-47's 7.62 mm round is effective at more than 400m. And the AK-47 is extremely durable, as are most of the other marks of Kalashnikov weapons. "You can dip it in the river, drop it in sand but it still works," an Afghan security contractor said.

In comparison, the M-4 fires a lighter 5.56mm round. "The 5.56mm calibre is more lethal since it can put more rounds on target," Colonel Douglas Tamilio, a programme manager at the US Army's centre for small arms development, told the Associated Press. "But at 500m to 600m the round doesn't have stopping power."

Nato sources said the alliance's soldiers use the M-4 "because it's a close-in weapon, since we anticipate house-to-house fighting in many situations". The M-4 worked well in Iraq, where much of the fighting was close-quarter battles in cities such as Ramadi and Fallujah. But in Afghanistan, some Taliban fighters will open fire at ranges of close to a kilometre. Taliban snipers held up US Marines and their Afghan comrades during Nato's operation to clear the farmlands of Marjah, in central Helmand, this year.

Among the solutions the US Army is proposing, is that nine soldiers in each infantry company carry the new M-110 sniper rifle, which fires a 7.62 mm and is accurate to more than 800m. Infantry companies already include sharpshooters with M-14s, and weapons teams carrying grenade-launchers and light machine-guns.

Another idea is to design a rifle with a heavier calibre than the M-4, trading in some of its high rate of fire for greater range. But some experts argue that the 5.56mm round is maligned by the US Army report. Instead, they say that the M-4's failings are the result of its shorterbarrel, which makes it easier for soldiers to wield as they scramble in and out of vehicles. The M-4 is a compacted version of the M-16 rifle, a more cumbersome weapon. "Unfortunately, weapon engineers shortened the M-16's barrel to irrational lengths," Martin Fackler, a ballistics expert, said. The British Army uses the 5.56mm SA-80, backed by the 7.62mm "gimpy", the general purpose machine-gun with a high rate of lethal fire.

But in the labyrinth of vineyards and orchards in Kandahar province, where much of this summer's fighting is expected, range is unlikely to be an issue. The dense vegetation lets insurgents get within 200m before opening up on Nato troops, well within the M-4's range.