Munitions

M549A1 rocket-assisted projectile

Also known as
  • M549A1 RAP
  • M549A1 HE RAP
  • M549A1 HE-RAP
  • 155 mm M549A1 HE-RAP
  • M549A1 Rocket Assisted Projectile

The M549A1 is a U.S. 155 mm high-explosive rocket-assisted projectile and the TNT-filled follow-on to the earlier Composition-B-filled M549. Army references describe it as a two-piece round with a high-fragmentation steel warhead and integral rocket motor, built to extend howitzer range to about 30 km and later treated as a legacy munition for replacement by XM1113. Conflict reporting also places M549A1 RAP in Ukrainian Bohdana howitzer combat use during the 2014 Russia-Ukraine War.

M549A1 rocket-assisted projectile, 155 mm high-explosive rocket-assisted projectile, Munitions
Image source: File:Sweeping without a broom 131029-M-Zs544-486.jpg

Role in Conflicts

Profile / Specs

Profile

Origin
United States
Type
155 mm high-explosive rocket-assisted projectile
Service note
Type-classified in 1977; legacy 1970s-1980s U.S. ammunition
Produced
Late 1970s-1980s

Specifications

Caliber
155 mm
Type
High-explosive rocket-assisted projectile
Weight
96 pounds
Payload
15 pounds of TNT
Maximum range
30 km from M198 and similar 155 mm systems
Propelling charges
M203A1, M119A2, MACS M232/M232A1, and/or M4A2
Rocket motor
About 6.5 pounds of solid rocket propellant
Construction
Two preassembled components: high-explosive warhead and rocket motor
Round Architecture And Designation

The A1 designation matters because public sources distinguish it from the earlier M549 by explosive fill and charge-safety context rather than by a new caliber or launcher class.

FeatureM549 contextM549A1 treatment
Explosive fillEarlier M549 rounds used Composition B.M549A1 uses about 15 pounds of TNT.
Type-classification driverThe earlier fill was restricted with newer top-zone M203 propelling-charge use.The A1 conversion was type-classified in September 1977 to satisfy safety requirements for newer 155 mm weapon systems.
Range roleBoth belong to the U.S. 155 mm rocket-assisted projectile family.M549A1 keeps the extended-range role with a high-explosive warhead and integral rocket motor.

Sources: M549A1 Rocket Assisted Projectile; PEO Ammunition 2017.

Firing Weapons

Army ammunition references and conflict reporting tie this legacy 155 mm projectile to U.S. howitzers and compatible NATO-standard systems.

Firing weaponWeapon typeFiring evidence
2S22 Bohdana, 155 mm wheeled self-propelled howitzer, Artillery2S22 Bohdana155 mm wheeled self-propelled howitzer

Army Recognition lists M549A1 RAP among the NATO-standard shells confirmed in combat use by Ukrainian Bohdana howitzers.

Sources: Bohdana 5.0 M549A1 combat-use report

M777, 155 mm towed howitzer, ArtilleryM777155 mm towed howitzer family

The Army ammunition portfolio identifies M549A1 compatibility with M777-series 155 mm field artillery.

Sources: PEO Ammunition 2017

M198 155 mm howitzer, 155 mm towed howitzer, ArtilleryM198 155 mm howitzer155 mm towed howitzer

Army ammunition data use M198-class firing tables for the round's roughly 30 km maximum range.

Sources: PEO Ammunition 2017, M549A1 Rocket Assisted Projectile

M109A6 Paladin, 155 mm tracked self-propelled howitzer, ArtilleryM109A6 Paladin155 mm self-propelled howitzer

The Army ammunition portfolio places M549A1 in the 155 mm ammunition set for M109A6 Paladin-era field artillery.

Sources: PEO Ammunition 2017

FH70 155 mm howitzer, 155 mm towed howitzer, ArtilleryFH70 155 mm howitzer155 mm towed howitzer

GlobalSecurity lists the M549A1 rocket-assisted projectile as ammunition for the FH-70 howitzer.

Sources: FH-70 - 155mm Howitzer

Timeline

M549A1 rocket-assisted projectile Key Events

  1. M549A1 type-classified

    The A1 conversion replaced the earlier M549 Composition B fill with TNT to meet safety requirements for newer 155 mm weapon and charge combinations.

    Sources: M549A1 Rocket Assisted Projectile

  2. XM1113 replacement effort described

    A U.S. Army article identified XM1113 as the planned successor to aging M549A1 RAP stocks produced in the 1970s and 1980s.

    Sources: Army developing safer, extended range rocket-assisted artillery round

  3. Reported in Bohdana combat use

    Army Recognition listed M549A1 RAP among the NATO-standard shells confirmed in combat use by Ukrainian Bohdana howitzers.

    Sources: Bohdana 5.0 M549A1 combat-use report

Media

M549A1 rocket-assisted projectile Images

M549A1 rocket-assisted projectile, 155 mm high-explosive rocket-assisted projectile, Munitions - view 1
Source: File:221st EOD Disposes UXO DVIDS50412.jpg
Related Weapon Systems
M106 203 mm high-explosive fragmentation projectile, 203 mm high-explosive fragmentation projectile, MunitionsMunitionsM106 203 mm high-explosive fragmentation projectile203 mm high-explosive fragmentation projectileThe M106 is a U.S. 8-inch, or roughly 203 mm, high-explosive fragmentation projectile built for American heavy artillery such as the M110. Open munition references describe a nose-fuzed, boat-tailed steel shell with TNT or Composition B filling, while Ukrainian and defense-reporting sources document M106 projectiles being adapted to Ukrainian 2S7 Pion guns during the 2014 Russia-Ukraine War as Soviet-pattern 203 mm stocks became scarce.
9M542 extended-range high-explosive rocket, 300 mm extended-range high-explosive fragmentation rocket, MunitionsMunitions9M542 extended-range high-explosive rocket300 mm extended-range high-explosive fragmentation rocketThe 9M542 is a Russian 300 mm extended-range high-explosive fragmentation rocket projectile for the 9K58 Smerch family and compatible modernized launchers. Missilery describes the export-oriented projectile as a deep upgrade of the 9M55K with an inseparable HE-fragmentation head, 820 kg projectile mass, 150 kg warhead, 70 kg explosive fill, 9B708 control-system unit, and 40 to 120 km range. Rostec later listed it as Splav-produced extended-range ammunition used in Smerch launchers at SITDEF-2013.
M107 155 mm high-explosive projectile, 155 mm high-explosive projectile, ArtilleryArtilleryM107 155 mm high-explosive projectile155 mm high-explosive projectileThe M107 is a conventional 155 mm high-explosive projectile with a forged-steel body, TNT or Composition B fill, and deep- or normal-cavity variants for different fuze fits. U.S. Army ammunition records list it as an operations-and-sustainment item, Modern War Institute reporting places the M107 family in Ukraine's 155 mm ammunition mix, and U.S. emergency-sale notices document M107 deliveries to Israel during the 2023 Israel-Hamas War.
155 mm artillery round, 155 mm artillery ammunition family, MunitionsMunitions155 mm artillery round155 mm artillery ammunition familyThe 155 mm artillery round is a family-level label for complete 155 mm howitzer shots rather than one projectile model. U.S. Army sources define a complete shot as fuze, primer, projectile, and propelling charge, while manufacturer and conflict records show high-explosive, extended-range, inert, precision-guided, smoke, illumination, cluster, white-phosphorus, and charge-system variants across NATO and NATO-compatible artillery use.
3OF50 High-Explosive Fragmentation rocket-assisted projectile, 120 mm rocket-assisted HE-fragmentation projectile, MunitionsMunitions3OF50 High-Explosive Fragmentation rocket-assisted projectile120 mm rocket-assisted HE-fragmentation projectileThe 3OF50 is a Soviet-era 120 mm rocket-assisted high-explosive fragmentation projectile for Nona-family gun-mortars such as the 2S9 Nona and 2S23 Nona-SVK. Specialist ammunition references describe a spin-stabilised, nose-fuzed projectile with an A-IX-2-filled warhead and integral rocket motor, while Ukraine explosive-ordnance identification material lists the round among munitions discovered on Ukrainian territory.

Sources

M549A1 Rocket Assisted ProjectilePublisher: Federation of American Scientists | Note: Supports the projectile's basic construction, TNT fill, and extended-range role for standard and developmental howitzers. | Accessed: 2026-06-29PEO Ammunition 2017Publisher: U.S. Army | Note: Supports the M549A1's two-part construction, TNT fill, rocket-motor details, propelling-charge compatibility, maximum range, and field-artillery compatibility. | Accessed: 2026-06-29Army developing safer, extended range rocket-assisted artillery roundPublisher: U.S. Army | Note: Supports the legacy-service context by identifying M549A1 rounds as 1970s-1980s ammunition slated for replacement by XM1113. | Accessed: 2026-06-29Rethinking Governance of the Army's Arsenals and Ammunition PlantsPublisher: RAND | Note: Supports U.S. ammunition-production context by listing an M549A1 production line at Iowa Army Ammunition Plant and identifying American Ordnance as the facility-use contractor tied to artillery shell manufacture there. | Accessed: 2026-06-29Bohdana 5.0 M549A1 combat-use reportPublisher: Army Recognition | Note: Supports 2014 Russia-Ukraine War direct conflict use by Ukrainian Bohdana units by naming M549A1 RAP among shells confirmed in combat use, and supports Bohdana 155 mm L52 compatibility context. | Accessed: 2026-06-29File:Sweeping without a broom 131029-M-Zs544-486.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and public-domain status for the primary M549A1 image. | Accessed: 2026-06-29File:221st EOD Disposes UXO DVIDS50412.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and public-domain status for the gallery image showing palletized M549A1 rounds. | Accessed: 2026-06-29FH-70 - 155mm HowitzerPublisher: GlobalSecurity | Note: Supports the FH70 relationship by listing the M549A1 rocket-assisted projectile as ammunition for the FH-70 howitzer. | Accessed: 2026-06-29