Colt CM901

About the Colt CM901

The Colt CM901 is a modular multi-caliber semi-automatic rifle designed to convert between 7.62x51mm NATO and 5.56x45mm NATO configurations without tools. The system uses a common 7.62mm lower receiver that accepts both a dedicated 7.62mm upper receiver and a standard 5.56mm M4-pattern upper through an adapter, allowing units to field a single weapon system that can serve as both a DMR and a standard carbine. The 7.62mm configuration features a 16-inch chrome-lined barrel with direct impingement gas system and a monolithic flat-top upper receiver with continuous Picatinny rail. Developed as a competitor in the US military's Individual Carbine program, the CM901 offered the military an upgrade path that maintained compatibility with existing M4 upper receivers and training while adding 7.62mm capability. The civilian variant is marketed as the LE901-16S.

The CM901 represented Colt's ambitious attempt to retain its dominance in US military small arms by offering a modular system that could replace both the M4 carbine and the M14 EBR in a single platform. When a soldier needed to reach out past 500 meters, they could swap to the 7.62mm upper; for close-quarters work, they could snap on a standard M4 upper. The concept was sound, but budget cuts killed the program before it could prove itself in the field.

Colt CM901 specifications

The CM901 was Colt's entry into the modular rifle market to compete with the FN SCAR and Remington ACR. Its unique selling proposition was backward compatibility with existing M4/M16 5.56mm upper receivers, which would have simplified military logistics. The rifle can achieve sub-2 MOA accuracy with standard M80 ball ammunition and sub-1 MOA with M118LR match ammunition. The select-fire military variant has a cyclic rate of 700-950 rpm. Despite positive reviews, the CM901 saw limited military adoption as the Individual Carbine program was ultimately cancelled in 2013 due to budget constraints. The LE901-16S civilian model is semi-automatic only.