US Precision Munitions Expenditure Rate Exceeds Replenishment Capacity During Iran Campaign

Technical Summary

The US Department of Defense (DoD) has acknowledged that precision-guided munitions (PGMs) expenditure during the US-Israel campaign against Iran, designated Operation Epic Fury, has exceeded pre-conflict stockpile projections. Senior Pentagon officials testified before the Senate Armed Services Committee on 24 March 2026 that the first six days of operations consumed approximately $11.3 billion in ordnance, a burn rate substantially above Cold War-era planning assumptions.

Munition types under acute depletion pressure include the GBU-57A/B Massive Ordnance Penetrator (MOP), a 13,600 kg GPS-guided penetrator carrying approximately 2,400 kg of high-explosive fill, assessed as Composition H-6 (RDX/TNT/aluminium). B-2 Spirit strikes against hardened Iranian nuclear facilities at Fordow and Natanz consumed an undisclosed number of GBU-57 weapons. Boeing has subsequently received a sole-source contract to manufacture replacement units. Additionally, the Lockheed Martin Joint Air-to-Surface Standoff Missile (JASSM-ER) and Tomahawk Land Attack Missile (TLAM) Block V stocks are reported below planned war reserve levels.

The DoD's $200 billion supplemental request to the Office of Management and Budget includes $28.8 billion specifically for munitions replenishment. Congress authorised multi-year procurement authority for eight missile types under the FY26 National Defense Authorization Act, intended to accelerate production rates. Framework agreements have been reached with BAE Systems, Lockheed Martin, and Honeywell to expand manufacturing capacity.

Analysis of Effects

The GBU-57A/B detonation against reinforced concrete targets generates estimated peak overpressure of 35,000–50,000 kPa at the point of burst, with a lethal radius (LR) extending to approximately 300 metres in open terrain. The weapon's 2,400 kg Net Explosive Quantity (NEQ) TNT equivalent classifies it as Hazard Division 1.1, Compatibility Group D (HD 1.1D) under NATO AASTP-1 storage and transport protocols. Fragmentation effects are secondary; the weapon's primary kill mechanism is blast overpressure transmitted through geological strata to defeat hardened and deeply buried targets (HDBTs).

Production-rate constraints for the GBU-57 are driven by the precision machining requirements for the weapon's 6-metre penetrator casing and the limited supplier base for the specialised explosive fill. Current US production capacity for PGMs across all types remains below the consumption rate observed during the first three weeks of operations, creating a projected stockpile deficit through at least FY2028.

Personnel and Safety Considerations

Accelerated munitions production introduces occupational hazard exposure risks across the US ammunition manufacturing base. Facilities handling Composition H-6 explosive fill must comply with DoD 4145.26 (DoD Contractor's Safety Manual) and MIL-STD-2105D for hazard classification. Increased throughput at Lake City Army Ammunition Plant (LCAAP) and the Mesquite, Texas second-source facility requires proportional scaling of explosive safety distances (ESDs), personnel exposure limits (PELs), and quality assurance sampling rates.

Ammunition Technicians and WOME practitioners monitoring allied procurement channels should note that US stockpile depletion has historically triggered accelerated Foreign Military Sales (FMS) diversions, potentially affecting NATO partner munitions availability. The US has previously redirected stocks earmarked for partner nations under pressure, as documented during the Ukraine drawdown from 2022 to 2024.

Data Gaps

AI-assisted technical assessment based on open-source material. Not a formal intelligence product. Classification: Open Source | AI-Assisted Technical Assessment.

ISC Commentary

Further analysis pending.