D
Land ForcesUnited States

M109A2

155mm self-propelled howitzerFielded 1978Pending verification
Land ForcesUSA
M109A2
Photo: Ad Meskens · CC BY-SA 4.0, Wikimedia Commons
Fact cardConfidence · Source
System
Type155mm self-propelled howitzer
Date of introduction1978
ProliferationAt least 5 countries
Crew6Med[1]
Dimensions and weight
Width3.28 m11 ftMed[1]
Height3.28 m11 ftMed[1]
Weight24.95 tMed[1]
Automotive performance
ChassisThe M108 and M109 shared a common chassis (along with the M113 APC), but the M109 was heavier and had a larger gunMed[1]
Engine1 x General Motors 8V-71T 569-cu in (9.32-liter) liquid-coolMed[1]
Engine power405 hpMed[1]
TransmissionAllison ATD-XTG 411-2A (A3) or 411-4 with quick disconnect powershift crossdrive, 4 forward and 2 reverse gearsMed[1]
Cruising range354 km220 mi · 191 nmiMed[1]
Max road speed56 km/h35 mph · 30 ktMed[1]
Fording depth1.07 mMed[1]
Suspensiontorsion bar, 7 road wheels, front drive, rear idler, no return rollers (all models except PIM)Med[1]
Protection
Hull ArmorLight alloy aluminum to protect against small-arms fire and shell splintersMed[1]
Turret ArmorThe turret takes up the rear. On top of the turret, there is a small cupola, from which the commander operates. This cupola is also fitted with a 12.7 mm (.50) M2HB heavy machine gun.Med[1]
Armament
Elevation-3/+75 deg (-53/+1,333 mils)Med[1]
Rate of fire (max)1 rd/min first hour; 4 rd in first 3 min maxMed[1]
Rate of fire (sustained)2 rpmMed[1]
Main armamentM185 155 mm/L39 howitzer, 155 mmMed[1]
Secondary armament1 x M2 Browning 12.7mm Heavy Machine GunMed[1]
Maximum firing range14.6 km9 mi · 8 nmiMed[1]
Fire control
Computerized FCSFire-control equipment includes an elbow telescope M118C for direct fire with a magnification of 4x and 10-degree field of view; panoramic telescope M117 for indirect fire and gunner's quadrant M1A1.Med[1]
Main Gun StabilizationYesMed[1]
Fire control systemIt has an all weather ballistic shield mounted over the panoramic telescope; counterbalanced travel lock and provisions for mounting the M140 alignment device.Med[1]
Variants
M109First 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[1]
M109A1Replaced the M126 gun with a longer barreled, 39 caliber M185 gun, increasing maximum range to 18,100 meters.[1]
M109A2Incorporated 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, [1]
M109A3 and M109A3BM109A1s and M109A1Bs were rebuilt to M109A2 standard respectively. Some A3s feature three contact arm assemblies, while all A2s have five.[1]
M109A4M109A2s 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[1]
M109A5Replaces 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[1]
Weapons and payload options · 3Confidence · Source
DPICM155mm ammunition
Med[1]
Range
22 km14 mi · 12 nmi
Quantity
36 Rounds Total of any Combination Projectiles
HE155 mm ammunition
Med[1]
Range
17.7 km11 mi · 10 nmi
Quantity
36 Rounds Total of any Combination Projectiles
RAAMS Long155 mm ammunition
Med[1]
Range
17.7 km11 mi · 10 nmi
Quantity
36 Rounds Total of any Combination Projectiles
Summary

The M109A2 incorporated 27 mid-life improvements to the M109A1. The improvements provide for increased Reliability, Availability, and Maintainability (RAM) and safety characteristics as well as enhanced operational capabilities.

Draft entry. Values come from the cited public sources and are awaiting editor verification.
CompareShow on range mapJSON
Operators
United StatesAustriaChinaLatviaTaiwan
Sources
  1. M109A2 American 155mm Self-Propelled Howitzer (SPH), U.S. Army TRADOC G-2 Worldwide Equipment Guide (ODIN)
    Published/updated 2026-03-20 · Tier 1 · checked 2026-10-10
Change log
  • 2026-10-10 Entry created from the Worldwide Equipment Guide (ODIN), bulk import
  • 2026-10-10 Added photo (CC BY-SA 4.0)