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Land ForcesUnited States

M109A3

155mm self-propelled howitzerFielded 1980Pending verification
Land ForcesUSA
M109A3
Photo: George E. Koronaios · CC BY-SA 4.0, Wikimedia Commons
Fact cardConfidence · Source
System
Type155mm self-propelled howitzer
Date of introduction1980
ProliferationAt least 14 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 ArmorINA, the 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]
NBC Protectionnone fittedMed[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, 155mmMed[1]
Secondary armamentM2 BrowningMed[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 id[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 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 Long155mm ammunition
Med[1]
Range
17.7 km11 mi · 10 nmi
Quantity
36 Rounds Total of any Combination Projectiles
Summary

The M109A3 is a depot converted M109A1 incorporating the 27 mid-life improvements. The operational characteristics of the M109A3 are virtually identical to the M109A2.

Draft entry. Values come from the cited public sources and are awaiting editor verification.
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Operators
United StatesBrazilDenmarkEgyptSpainGreeceJordanLebanonMoroccoNorwayPakistanPortugalSaudi ArabiaTunisia
Sources
  1. M109A3 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)