M549
| 155 mm M549 HERA | |
|---|---|
| Color-coded section view of a rocket-assisted projectile ammunition round | |
| Type | Rocket-assisted projectile | 
| Place of origin | United States | 
| Service history | |
| In service | 1970–present | 
| Production history | |
| Designed | 1960s | 
| Manufacturer | General Dynamics Ordnance and Tactical Systems | 
| Specifications | |
| Mass | 96 lb (43.6 kg) | 
| Length | 
 | 
| Diameter | 155 mm (6.1 in) | 
| Muzzle velocity | 2,710 ft/s (826 m/s) | 
| Maximum firing range | 18.7 mi (30.1 km) | 
| Filling | |
| Filling weight | 
 | 
| References | Janes | 
The M549 is a high-explosive rocket-assisted (HERA) 155 mm howitzer round developed for use by the US military in order to add additional range to standard howitzers, with a maximum range 30.1 km (18.7 mi) from a M198 howitzer. The projectile has two distinctive pre-assembled components—the high-explosive (HE) warhead and the rocket motor, making it a form of rocket-assisted projectile. The warhead is fabricated from high-fragmentation steel for increased effectiveness in terms of damage caused to target and contains a bulk-filled explosive (either TNT or Composition B).