Rifles favoured by the US Army will go under testing in sandstorm conditions following applied pressure by a US senator.
In August, the M4 carbine will be tested in a 'dust chamber' which replicates sandstorms conditions. The testing is expected to cost $500,000 over five months, industry website armytimes.com reported.
The M4's performance will be compared with the Heckler & Koch 416, the H & K XM8 and FNH USA's Special Operations Forces Combat Assault Rifle.
Senator Tom Coburn questioned the Army's decision to spend $375m on M4 rifles in April. Since then he has threatened to hold up former Democratic congressman Peter Geren's confirmation as the new US Army secretary.
Under American law, one senator can hold up a nomination. The Senate confirmed Mr Geren's position on July 13 after the tests were agreed to.
By staff writer