Hypervelocity Improved Capability Assault Rifle (HICAR) Amendmendent 0001 This amendent is issued to extend the deadline for solution brief (also known as white paper submission) to June 12th at 1400 EDT. The Questions and Answers for this AOI are hereby attached and the link to the original CSO is hereby posted here: https://sam.gov/opp/09cb891ea16a41ab8386c552140b4740/view PROBLEM STATEMENT USSOCOM is seeking a carbine system to act as a replacement or upgrade for the current URG-I (Upper Receiver Group - Improved). The goal is to integrate advancements in material science and weapon design to provide operators with a technically superior individual weapon system capable of firing both legacy 5.56x45mm NATO and emerging hyper velocity ammunition. The current URG-I is an M4-based platform optimized for standard 5.56NATO ammunition, with a recognized effective range of approximately 300 meters. Special Operations Forces (SOF) require the ability to provide effective fire on targets with their primary 5.56mm carbine out to 600 meters and beyond. This weapon system will allow an operator to effectively engage targets at extended distances while maintaining the portability and ergonomics of a lightweight carbine. The Hypervelocity Improved Carbine (HICAR) program will develop an improved carbine capable of operating with currently issued 5.56NATO ammunition, while also incorporating design features that ensure reliability, durability, and longevity with the use of future hypervelocity 5.56x45mm ammunition. The ability to leverage the performance benefits of current and future experimental hypervelocity rounds is vital to addressing future capability gaps on the battlefield. Weapon submissions that address the following technology priorities will benefit during the selection process: Hypervelocity Ammunition Compatibility : The ability to accept and reliably cycle both 5.56NATO and hyper velocity 5.56x45mm ammunition is a primary objective. The development of a complete weapon system or conversion kit optimized for hypervelocity ammunition will be a collaborative effort between the government and the proposer. Hypervelocity rounds offer significant performance benefits, including: Increased Effective Range: Higher muzzle velocity allows the projectile to maintain kinetic energy over longer distances, extending the effective range to 600m+. Improved Terminal Performance: Enhanced energy transfer upon impact leads to more effective terminal ballistics. Enhanced Barrier Penetration: The increased velocity and kinetic energy enable the projectile to more effectively defeat body armor, barriers, and other hardened surfaces. Longevity and Durability : The system must be engineered to withstand the increased chamber pressures and bolt thrust generated by hypervelocity ammunition without compromising the weapon's service life or operator safety. Interoperability: The system must remain fully interoperable with USSOCOM's existing suite of Visual Augmentatio…