The M109A1 was introduced into American service in 1973 as an improved version of the M109 self-propelled howitzer. The main improvement was the installation of a new 155 mm M185 cannon, which had a longer barrel and a higher muzzle velocity than the previous M126, increasing the effective range of the M109A1 from 14.6 km to 18 km, giving it an advantage over foreign artillery. Where this tank lacks in armor and survivability, it makes up for with a powerful armament and choice of chemical rounds that can overpressure any tank, and even knock out aircraft from the skies.
| Pros: | Cons: |
| Powerful armament; access to heavy chemical rounds to overpressure | Long reload speed and slow turret traversal |
| Decent mobility and acceleration | Paper-thin armor; susceptible to overpressure |
| Access to proximity fuse HE | Proximity fuse requires distance before activating against air targets |
Armor and Survivability:
Armor is not on the side of the M109A1, as both the turret and hull have near paper-thin armor, only being able to survive light machine gun fire, but giving way to heavy machine gun fire. On one hand, AP rounds that would normally destroy this tank will pass through, leaving little damage inflicted on this tank. On the other hand, any chemical round of sorts (excluding smoke rounds) will overpressure this tank, knocking out the entire crew. The M109A1 is also susceptible to air attacks, so any chemical munitions or strafing fire from aircraft will destroy it equally.
The crew of the M109A1 is slightly spaced out from each other, giving a small bonus towards survivability. On top of that, the large crew count of 6 gives a bonus to crew survivability, easily replacing one crew member should they get knocked out. The driver sits on the engine's left, away from the gunner, commander, and the three loaders. Try not to bring too much ammo, as an M109A1 with full ammo is a powder keg waiting to be detonated.
| Armor (mm): | Front | Side | Rear |
| Hull | 32 | 32 | 32 |
| Turret | 32 | 32 | 32 |
Mobility:
Thanks to its paper-thin armor and strong engine, the M109A1 has an impressive forward speed of 56km/h, allowing it to transport it from one position of the map to another is a reasonable amount of time. The reverse speed of -6km/h, on the other hand, is a hindrance when attempting to retreat backwards, but is enough to pull out of most combat areas. Make sure to keep these in mind when engaging or disengaging enemy targets.
Firepower and Ammunition:
Unlike the short, stubby cannons on the earlier variants, the main improvement of the M109A1 was the installation of a new 155 mm M185 cannon, which had a longer barrel and a higher muzzle velocity than the previous M126. Despite the new improvement, the SPG retains a very long reload of 17.28 seconds. Since it's paired with a slow turret traverse rate of 6.5°/s, terrible gun depression of 3°, and a poor gunner zoom magnification of 4.0x, it makes long-range engagements a rather difficult task, but not unachievable. Along with the main gun is a .50cal M2HB heavy machine gun which is helpful for clearing obstacles and shooting down lightly armored vehicles or aircraft.
| Ammo Name: | Ammo Type: | Penetration Value: | Info: |
| M107 | HE | 61mm | The stock round of the M109A1, M107, is an essential chemical round with a hefty explosive mass of 7.0t and a decent penetration of 61mm against armor. For many players, 61mm of penetration doesn't seem helpful in the BR it fights in, since it's a typical penetration value normally seen in lower tiers. However, paired with its large explosive mass, it can overpressure certain weakspots that are otherwise impenetrable by conventional means (Vehicle underside, machine guns, commander cupola, etc.). |
| M107 (PF) | HE-VT (Proximity Fuse) | 61mm | The next round of the M109A1, M107 (PF), is the same as the stock version, only being fitted with a proximity fuse for combatting air targets. The hefty amount of explosive mass and the fuse activating when the aircraft gets close often results in the aircraft or helicopter turning into a burning scrap. Keep in mind that the fuse only arms after it has been launched 200 meters into the sky, as well as careful placement of the round at air targets being needed. |
| M110 | Smoke Round | 3mm | The last round of the M109A1, M110, is a smoke round useful only for concealment purposes, whether to assist allied players or blind enemy targets. |
Playstyle:
Due to its thin armor, long reload, and big gun with chemical rounds only available, there are two viable engagement playstyles the M109A1 can excel at:
Support: This is the best target engagement method, as it safely assists allied players from a distance or from behind, either crippling enemy vehicles for teammates to finish off, or destroy them while the teammate is critically hit. Just remember that there may be other players on the enemy side acting as support, so check your surroundings while supporting your team.
Anti-Aircraft: This method requires some finesse, as the aircraft you'll face will be jet-powered, giving them more speed and evasiveness. Luckily, with the proximity fuse HE round equipped, this shouldn't be an issue, as with careful aim and distance, you can knock out the plane in the sky before it attacks the SPG or allied vehicles.
Enemies Worth Noting:
Aside from the fact that even a Rank I vehicle can destroy this tank, this tank can be shot down by any armament from any vehicle, whether it be strafing fire from HMGs on enemy aircraft, chemical rounds from enemy ground targets, or even indirect artillery fire splashing around the SPG.
Light vehicles like the FIAT 6614 and Pbv 501 possess chemical rounds that can overpressure the paper-thin armored SPG, while other light vehicles like the AMX-13 possess solid AP rounds that generate huge amounts of spall due to thin armor. Luckily, with the HE round equipped by the M109A1, these vehicles pose less of a threat, so long as players mind their surroundings and react appropriately.
Medium targets like the Centurion Mk.1, the T-44, and the Panther Family all possess penetrative rounds that can penetrate and will destroy the M109A1 like the light targets, but may overpenetrate due to the high penetration value of their shells and may cause minimal damage.
Heavy vehicles like the IS-2, Tiger II, and the AMX-50 Surbaissé all have nigh impenetrable armor, with the front and sides having protection against the heavy HE round of the M109A1, but similarly to medium vehicles, their penetrative rounds can overpenetrate and cause minimal damage to the SPG, and their slow turret traversal can also allow the vehicle to flank these battle beasts and take them out from the rear.
Enemy aircraft that pose a threat range from strafing fighters like the Fw-190 and Yak-3, to strike aircraft and bombers such as the He 177 A-5 and Me 262 A-1/U4. Fortunately, with the proximity-fuse HE round equipped, the M109A1 can shoot said targets out of the sky, though it'll require some finesse due to the long reload and slow turret traversal.
Tips and Tricks
There are a couple of tips and tricks that one can use for players wanting to maximize the most of the M109A1 experience:
- Aim the crosshair below a medium or heavy target and lob a HE round underneath, as it'll overpressure the tank from the belly, which is always the weakest part of the tank. Do note that some tanks have elevated bodies, as to prevent such a situation from killing them.
- When aiming the crosshair at a diving aircraft heading towards the SPG, make sure to equip the proximity round and aim slightly above the aircraft to guarantee a hit, as aiming the crosshair directly on the and firing will force the shell to go under the aircraft and leave the M109A1 to the mercy of enemy aircraft fire.
Variants
In addition to the M109A1, there are a couple of other variants that are alike to the American SPG:
- M109A1 (Great Britain): Same configurations as the American variant, only difference being the color.
- Rochev (Israel): Similar to the American and British SPG, it boasts the same configuration and firepower as the M109A1. The difference is the addition of add-on items on the turret and hull and the possession of more machine guns to take out obstacles, tracks, and lightly armored targets.
- M109: These variants, particularly only in Germany, Italy, and Israel, have the same configuration as the M109A1 and its parallel variants with differences. The important difference separating the M109s from the M109A1s is the main gun, with the M109 boasting a shorter and stubbier gun in comparison to the M109A1's longer gun barrel. While all the other M109s have a muzzle velocity of 684 m/s, the Israeli M109 has a slightly lower muzzle velocity of 562 m/s.
- XM975: On top of a modified M109 chassis, this vehicle is outfitted with the Roland SAM System, replacing the familiar paper-thin turret, and replacing it with a quicker turning one. Instead of a main gun firing chemical rounds, it fires Roland 1 and 3 SAMs (Surface-To-Air Missiles) that allow to shoot down enemy aircraft thanks to its proximity fuse, the large explosive mass, and the helpful guidance system being SACLOS (Semi-Auto Command Line of Sight) for easier control of the missile towards air targets.
