The U.S. Army is seeking ways to extend the reach of 155mm systems with 39-caliber barrels – such as the M777 towed howitzer and the M109 self-propelled howitzer – to 40 km. To do that, it wants to develop new rocket-assisted rounds under the Next Generation Rocket-Assisted Projectile (NGRAP) program.
The request surfaced via sources linked to Army Command in New Jersey. The requirement is for a universal round compatible with existing fuzes and propellant charges.
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For 39-caliber barrels the target is at least 40 km in unguided mode and 36 km in guided mode – sufficient for the M777 and M109 families that form the backbone of U.S. tube artillery. Today, these weapon systems typically reach roughly 30 km with current rocket-assisted projectiles, while the 40 km mark is already achievable using the high-cost, precision guided M982 Excalibur. Excalibur's price and susceptibility to EW explain why the Army is searching for an alternative.
Though the U.S. is not fielding many 52-caliber tube systems (like Ukraine's 2S22 Bohdana), the request also references longer-barrel guns: for 52-caliber tubes the goal is ~48 km guided and up to ~55 km unguided. That ties into new and modernized platforms under development or test, including wheeled SPGs and an M109-52 upgrade equipped with a PzH 2000-type gun.
Early operational capability is expected in FY2027, with full fielding planned for FY2030. Those dates are predicated on selecting high-readiness solutions that require minimal redesign.
The U.S. also lists intended targets for the new rounds beyond standard infantry and armored formations – radar installations and air-defense systems are explicitly mentioned. That implies a possible need for even greater range for some missions.
Production is another open question. Current estimates range wildly – from about 500 to 15,000 rounds per year – depending on the chosen variant, unit cost, and degree of specialization. Even the high end of that range appears modest compared with battlefield ammunition consumption in Ukraine. By comparison, annual Excalibur production already exceeds 14,000 rounds – and that is a specialized guided munition. An unguided, cheaper rocket-assisted round would need even higher production to meet demand.
In short, longer-range 155mm fires are strategically valuable in an era of drone dominance, especially for 39-caliber systems. Ukraine may well be interested in such a program – but any decision should weigh cost, producibility, and the political/diplomatic dynamics of arms cooperation with the United States.
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