American Rheinmetall Munitions recently unveiled the HAMMR (Highly-Advanced Multi-Mission Rifle), a 40 mm system based on the SSW40 grenade launcher, which the company has been developing since 2022. HAMMR was designed as a system combining the weapon, ammunition and fire-control system, and Rheinmetall has announced that it has submitted HAMMR as its proposal for the U.S. Army’s Precision Grenadier System program.
The SSW40 was first publicly unveiled at Eurosatory 2022. Rheinmetall designed the grenade launcher as a weapon operated by a single soldier and chambered for 40 mm Medium Velocity ammunition. The weapon is approximately 80 cm long and weighs around 4 kg without ammunition. It features a break-open barrel, magazine feed and a recoil mitigation system, while its ergonomics are intended to resemble those of an assault rifle. During the SSW40 demonstration, Rheinmetall engaged targets positioned at ranges of 100, 200, 300 and 500 m, as well as a vehicle wreck located 250 m from the firing position. According to the manufacturer, targets at 500 m were also successfully engaged.
HAMMR uses solutions previously developed for the SSW40, including Medium Velocity ammunition. Rheinmetall developed it as an intermediate solution between conventional 40 mm Low Velocity rounds and the heavier 40 × 53 mm High Velocity ammunition. According to the manufacturer, MV rounds offer a flatter trajectory, higher velocity and greater range than conventional LV rounds. For the SSW40, Rheinmetall states a range of up to 900 m. The 40 mm Medium Velocity family includes 10 variants, including High-Explosive Fragmentation rounds, Multi-Mission rounds and HEDP rounds. In the case of HEDP, the manufacturer states that it can penetrate approximately 10.2 cm of rolled homogeneous armor. The Multi-Mission ammunition family also includes a round using non-energetic tungsten balls, which can be used, among other applications, in urban and trench warfare, as well as against small drones at ranges exceeding 100 m. At the same time, HAMMR remains compatible with all qualified 40 mm Low Velocity rounds currently in the U.S. Army’s inventory.
HAMMR also incorporates the magazine feed and recoil mitigation system known from the SSW40. The grenade launcher can use 13-round or five-round magazines, while the launcher itself features a self-regulating hydropneumatic system that allows the use of more powerful Medium Velocity ammunition while retaining the characteristics of a weapon carried and operated by a single soldier.
One of the key elements of HAMMR is the Aimpoint FCS15 fire-control system, which assists with aiming and the use of programmable ammunition. Combined with airburst rounds, it allows targets behind cover to be engaged without requiring a direct hit on their position. According to Rheinmetall, the system also increases the effective range of fire. The FCS15, Medium Velocity ammunition and the weapon itself have been developed in parallel from the outset as components of a single system. The manufacturer also envisions using HAMMR to engage unmanned systems, supported by software capable of tracking them.
The system was developed in response to the requirements of the U.S. Army’s Precision Grenadier System program, which aims to develop a portable, semi-automatic, magazine-fed system operated by a single soldier and capable of precisely engaging targets at ranges from approximately 35 m to at least 500 m, both in the open and behind cover. Among the key requirements are a projectile flight time to 500 m of no more than three seconds, a system length of less than 34 inches, and a weight of less than 14.5 pounds including the fire-control system and power source. In 2026, the U.S. Army launched the formal process for the PGS prototype.
Photos: American Rheinmetall
