{
  "id": "m109a1",
  "name": "M109A1",
  "aliases": [],
  "domain": "land",
  "country": "USA",
  "category": "155mm self-propelled howitzer",
  "status": null,
  "fielded": 1970,
  "operators": [
    "USA",
    "ARE",
    "CHE",
    "DJI",
    "ETH",
    "GRC",
    "IRN",
    "KWT",
    "MAR",
    "OMN",
    "PER",
    "THA"
  ],
  "prolif_count": 12,
  "summary": "The M109A1 variant features an improved gun—the M185 155 mm/L39 howitzer. This artillery system was introduced in 1970 and deliveries commenced in 1973.",
  "specs": [
    {
      "k": "crew",
      "v": 6,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Chassis",
      "section": "mobility",
      "v": "The M108 and M109 shared a common chassis (along with the M113 APC), but the M109 was heavier and had a larger gun",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "width_m",
      "v": 3.15,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "height_m",
      "v": 3.28,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "combat_weight_t",
      "v": 24.07,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium",
      "label": "Weight"
    },
    {
      "k": "engine_name",
      "v": "Detroit Diesel 8V71T Diesel",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "engine_hp",
      "v": 450,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "road_range_km",
      "v": 390,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "speed_road_kmh",
      "v": 65,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Fording depth",
      "section": "mobility",
      "v": "1.07 m",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Elevation",
      "section": "armament",
      "v": "-3/+75 deg (-53/+1,333 mils)",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Rate of fire (max)",
      "section": "armament",
      "v": "4 rpm",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Rate of fire (sustained)",
      "section": "armament",
      "v": "2 rpm",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Main Gun Stabilization",
      "section": "firecontrol",
      "v": "Yes",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "Hull Armor",
      "section": "protection",
      "v": "The M109’s protection consists of up to 32 millimeters of armor, which is only effective against small arms and grenade/artillery fragments.",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "",
      "label": "NBC Protection",
      "section": "protection",
      "v": "none fitted",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "main_armament",
      "v": "M185 155 mm/L39 howitzer, 155 mm",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "armament",
      "label": "Secondary armament",
      "v": "M2 Browning",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium"
    },
    {
      "k": "range_max_km",
      "v": 14.6,
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium",
      "label": "Maximum firing range"
    }
  ],
  "payloads": [
    {
      "name": "Copperhead",
      "role": "155 mm ammunition",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium",
      "caps": {},
      "qty": "28 Rounds Total of any Combination Projectiles"
    },
    {
      "name": "DPICM",
      "role": "155 mm ammunition",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium",
      "caps": {},
      "qty": "28 Rounds Total of any Combination Projectiles"
    },
    {
      "name": "RAAMS Long",
      "role": "155 mm ammunition",
      "src": [
        "weg-m109a1"
      ],
      "conf": "medium",
      "caps": {},
      "qty": "28 Rounds Total of any Combination Projectiles"
    }
  ],
  "variants": [
    {
      "name": "M109",
      "text": "First produced in 1963. It had a 23 caliber 155 mm M126 gun in an M127 Howitzer Mount and carried 28 rounds of 155 mm ammunition. It was also armed with a .50cal M2HB machine gun with 500 rounds of ammunition. Easily ide",
      "src": [
        "weg-m109a1"
      ]
    },
    {
      "name": "M109A1",
      "text": "Replaced the M126 gun with a longer barreled, 39 caliber M185 gun, increasing the maximum range to 18,100 meters.",
      "src": [
        "weg-m109a1"
      ]
    },
    {
      "name": "M109A2",
      "text": "Incorporated 27 Reliability, Availability, and Maintainability (RAM) mid-life improvements. Most notably, the long-barreled 155 mm M185 cannon in the new M178 gun mount, ballistic protection for the panoramic telescope, ",
      "src": [
        "weg-m109a1"
      ]
    },
    {
      "name": "M109A3 and M109A3B",
      "text": "M109A1s and M109A1Bs were rebuilt to M109A2 standard respectively. Some A3s feature three contact arm assemblies, while all A2s have five.",
      "src": [
        "weg-m109a1"
      ]
    },
    {
      "name": "M109A4",
      "text": "M109A2s and M109A3s improved with Nuclear, Biological, and Chemical / Reliability, Availability, and Maintainability (NBC/RAM) improvements, including air purifiers, heaters, and Mission Oriented Protective Posture (MOPP",
      "src": [
        "weg-m109a1"
      ]
    },
    {
      "name": "M109A5",
      "text": "Replaces the 155 mm M185 cannon in an M178 mount with a 39-caliber 155 mm M284 cannon in an M182 mount, giving the A5 a maximum range of 22,000 meters with unassisted projectiles and 30,000 meters with Rocket Assisted Pr",
      "src": [
        "weg-m109a1"
      ]
    }
  ],
  "art": "sph",
  "image": null,
  "verified": null,
  "changelog": [
    {
      "date": "2026-10-10",
      "change": "Entry created from the Worldwide Equipment Guide (ODIN), bulk import"
    }
  ],
  "url": "https://www.defensepedia.com/systems/m109a1.html",
  "sources": {
    "weg-m109a1": {
      "title": "M109A1 American 155mm Self-Propelled Howitzer (SPH)",
      "publisher": "U.S. Army TRADOC G-2 Worldwide Equipment Guide (ODIN)",
      "url": "https://odin.t2com.army.mil/WEG/Asset/M109A1_American_155mm_Self-Propelled_Howitzer",
      "published": "2026-03-20",
      "tier": 1,
      "checked": "2026-10-10"
    }
  }
}