US Special Forces Seeking to Develop New HICAR High-Velocity Assault Rifle

The US Special Operations Command (USSOCOM) has announced a search for industry partners to develop a carbine intended to replace the existing M4A1 URG-I and capable of delivering effective fire with 5.56 mm rounds at ranges of 600 meters and beyond.

This information came to light through an announcement published on the US government procurement platform SAM.gov.

The goal is to integrate advancements in materials science and weapons design to provide the military with a more technically advanced individual weapon system.

The Hypervelocity Improved Carbine (HICAR) program involves the development of an improved carbine capable of firing both existing 5.56 NATO ammunition and future 5.56×45 mm hypervelocity rounds. The design is intended to ensure the reliability, durability, and service life of the weapon when using such ammunition.

Key features of the HICAR

The new assault rifle must be compatible with 5.56×45 mm rounds and capable of being mounted and operated with the M4A1 lower receiver without irreversible modifications.

The HICAR must fire and function with M855A1, Mk262, and M855A1+ hypervelocity ammunition with pressures up to 82 kpsi, as well as future hypervelocity ammunition designs.

The barrel must be 11 to 12 inches long, measured from the open muzzle to the bolt face. The HICAR must use the HUXWRX Flow 556k L silencer in the Black Magic version to reduce visibility until requirements for an optimized silencer are established.

Accuracy must be no worse than one minute of angle (1 MOA) when firing without a suppressor. Accuracy of 0.5 MOA is preferred.

The weight without ammunition and without a silencer must not exceed 8 pounds (3.63 kg), preferably 6.5 pounds (2.95 kg). The length, measured from the end of the stock tube to the end of the muzzle device, must not exceed 31 inches, preferably 28 inches.

The barrel life must be at least 8,000 rounds, preferably up to 20,000 rounds of M855A1+ ammunition. The weapon must maintain full functionality in all environments at temperatures ranging from -40 °C to 73.9 °C.

If the prototype is manufactured outside the United States, the developer must provide an industrialization plan for the production of the HICAR in the United States prior to the completion of the contract. According to the plan, selected suppliers will be invited to present and demonstrate their products in September 2026.

As a reminder, the US Army is preparing to introduce the new XM8 compact rifle to replace the M4. The first units are expected to receive the weapon as early as October 2026 as part of the infantry and assault team rearmament program.