More units of Chile's armed forces are using the M4 carbine, the standard infantry weapon of U.S. forces and other nations. The marine special forces is one such unit, as seen in this photo. (The weapon is seen fitted with the M-203 grenade launcher.) The M4 has its share of critics, though. Some soldiers complain it jams frequently in dusty, desert areas. U.S. troops in Afghanistan say their guns have malfunctioned at critical times. With similar conditions in the north of Chile, is the M4 the most adequate rifle? Most Chilean army soldiers still employ the SIG 540 5.56mm rifles, built under license by Famae. Rumors of Chile acquiring the HK416 or the SIG556 haven't materialized. UPDATE: Chile is seeking to acquire up to 15,000 assault rifles to replace older ones, Enfoque Estrategico reported. A competition between the Colt M4 and the Heckler & Koch G36C is planned.