BAE’s new M109A7 52 caliber howitzer gives U.S. Army Paladin long-range capability.

BAE Systems has introduced the new M109A7 52 caliber self-propelled howitzer, pairing the M109A7 Paladin howitzer tracked chassis with Rheinmetall’s L52 155mm cannon to significantly increase range. The design marks a quick-turn solution for the U.S. Army’s long-range fires gap following the ERCA program’s halt.

Washington D.C., United States, October 19, 2025 - BAE Systems is offering the U.S. Army a practical upgrade in its pursuit of extended-range firepower. The company’s new M109A7 52 caliber self-propelled howitzer prototype combines the proven M109A7 Paladin howitzer tracked chassis with the German Rheinmetall 155mm L52 cannon, delivering greater range and rate of fire while maintaining full logistical compatibility with existing fleets.
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BAE Systems showcases the M109A7 52-caliber self-propelled howitzer, featuring the 155mm 52-caliber Rheinmetall gun integrated on the M109A7 chassis, during the AUSA 2025 exhibition in Washington, D.C., marking a key step in U.S. Army artillery modernization. (Picture source: Army Recognition Group)

The M109A7 is the latest iteration of the long-serving M109 Paladin series and serves as the U.S. Army’s primary tracked self-propelled howitzer. It provides indirect fire support to armored brigade combat teams with improved survivability, mobility, and power generation compared to earlier models. Built on a modified Bradley Fighting Vehicle chassis, the M109A7 integrates a fully electric gun drive system, enhanced digital fire control, and upgraded onboard diagnostics. Crucially, it maintains compatibility with the legacy 39-caliber 155mm howitzer, while offering a modernized platform ready for growth, such as the integration of longer-range cannons like the L52. With the Army prioritizing maneuverability and rapid response in large-scale combat operations, the M109A7 serves as the foundational platform for future artillery capability enhancements like the M109A7 52 caliber.

This new platform is not just a speculative prototype. It is a deliberate blend of combat-tested hardware and NATO-standard firepower. After years of struggling with the technical risks of experimental artillery concepts, BAE Systems has opted for a lower-risk integration that could fast-track the U.S. Army’s long-range fires gap closer to operational readiness.

Unlike the now-cancelled ERCA platform, which ran into technical bottlenecks including rapid barrel degradation and excessive system weight, the M109A7 52 caliber takes a pragmatic path forward. By grafting the proven Rheinmetall L52 long-barrel cannon onto the M109A7’s digital fire control and robust electric-drive chassis, the system promises a significant leap in range without redesigning the entire vehicle architecture. BAE officials describe the project as leveraging mature subsystems while doubling down on NATO compatibility. The L52 cannon is already in frontline use with platforms such as the German PzH 2000 155mm self-propelled tracked howitzer and the Swedish Archer, making it a logical choice for cross-force interoperability.

From a technical perspective, the leap in performance is substantial. The current M109A7, armed with a 39-caliber gun, delivers effective fire at roughly 23 kilometers using standard high-explosive rounds and about 30 kilometers with rocket-assisted projectiles. With the Rheinmetall L52 integrated, the unassisted range extends beyond 30 kilometers, while rocket-assisted rounds reportedly reach as far as 60 kilometers. This effectively doubles the operational fire envelope and could significantly alter force posture at the brigade level. While those figures are subject to continued field validation, they reflect real potential to regain the standoff advantage in peer-level engagements.

The M109A7 52 caliber’s development is being advanced under a Cooperative Research and Development Agreement (CRADA) with the U.S. Army’s Combat Capabilities Development Command Armaments Center (DEVCOM-AC). Testing milestones include successful live-fire trials at Camp Ripley, Minnesota, where the new cannon was mounted and fired from the M109A7’s existing turret structure. Early reports confirm full mechanical integration with the vehicle’s existing recoil system and gun mount, a critical factor in limiting development costs and simplifying eventual fielding.

This program also carries significant strategic weight. The failure of ERCA left a conspicuous gap in the Army’s long-range precision fires modernization roadmap. The M109A7 52 caliber appears to fill that void not by revolutionizing artillery, but by upgrading what already works. That reflects a broader shift inside Army Futures Command, a move away from moonshot programs toward more incremental, achievable modernization that can withstand congressional scrutiny and budgetary pressure.

The adoption of a foreign-made cannon also signals a notable shift in acquisition philosophy. For decades, U.S. ground systems have relied almost exclusively on domestic cannon designs. By integrating Rheinmetall’s L52, BAE and the Army are accepting that in a race for capability, allied solutions may sometimes offer the fastest path to the battlefield. That could have ripple effects on domestic cannon producers and the broader U.S. artillery industrial base.

However, questions remain about long-term sustainability. The L52’s barrel, while proven, may still face wear issues under sustained firing conditions. Autoloader integration remains uncertain. The current M109A7 52 caliber configuration appears to retain manual loading, which could limit rate of fire in high-intensity operations. And while the system enhances range, accuracy and lethality will depend heavily on integration with the Army’s wider networked fires architecture, including sensors, targeting systems, and real-time data links.

It is also unclear how soon the M109A7 52 caliber could enter serial production or at what scale. BAE has not released unit costs or production timelines, though the use of existing vehicle platforms is expected to help contain overall program expense. Still, any decision to procure the system at scale would likely come as part of the FY2026 or FY2027 U.S. defense budget cycles.

In operational terms, the M109A7 52 caliber is a meaningful bridge, not a destination. It brings immediate improvements in range and coalition interoperability while the Army continues developing longer-range systems like Precision Strike Missile (PrSM) variants and extended-range rocket artillery. For heavy brigade combat teams, however, it may restore the relevance of tracked self-propelled artillery in high-intensity, contested domains, particularly in Europe or the Indo-Pacific.

This development reflects a broader recalibration of the U.S. Army’s fires modernization priorities. Having learned the hard lessons of ERCA, the M109A7 52 caliber represents a disciplined, evolution-based approach. It leverages field-proven technology, cross-NATO standardization, and rapid integration timelines to meet urgent operational needs. It is not revolutionary, but it might be exactly what the Army needs right now: range, reliability, and readiness without the risks of reinvention.

Written by Alain Servaes – Chief Editor, Army Recognition Group
Alain Servaes is a former infantry non-commissioned officer and the founder of Army Recognition. With over 20 years in defense journalism, he provides expert analysis on military equipment, NATO operations, and the global defense industry.