Description

The M1A1 Abrams is an upgrade of the M1 USA third-generation main battle tank. The M1 was named after General Creighton Abrams. With a weight of almost 62 metric tons, it's one of the heaviest main battle tanks in service. The M1A1 upgrade added a pressurized NBC system.

The M1A1SA (Situational Awareness) upgrade incorporates new 3rd generation Heavy Armor Package, new fire control system and sights including 2nd generation FLIR, commander FBCB2/BFT system display, improvements to commander CWS (Commander Weapon Station), new ammo racks and other minor upgrades bringing it nearly to M1A2SEP level.

Further armor protection can be improved with TUSK (Tank Urban Survivability Kit) which contains M19 ARAT-1 (Abrams Reactive Armor Tiles – 1) ERA (Explosive Reactive Armor) modules over hull sides, M19 modules are multilayer ERA type which provides high degree of protection against shaped charges with single warhead, and also some degree of protection against tandem warheads.

M1A1FEP (Firepower Enhancement Package) is USMC equivalent to US Army/ARNG M1A1SA, it differs however in smoke grenades dischargers type (US Army/ARNG uses M250, USMC uses M257) and other minor modifications. The M1A1HC (Heavy Common) is an older variant developed for both US Army and USMC, first vehicles left factory in 1990, and serving within USMC took part in 1991 Operation Desert Storm. It was the first variant that used 2nd generation Heavy Armor Package followed by late production M1A1HA (Heavy Armor) and baseline M1A2. M1A1HC was also the first variant which was redesigned to use DWFK (Deep Water Fording Kit) enabling it to ford deeper water obstacles. Vehicle however did not received sights and FCS upgrade over the previous variants.

The M1A1 features a powerful gas turbine engine, Honeywell AGT-1500 being able to produce 1500HP coupled with modern X-1100-3B hydrokinetic transmission, this powerpack can use a variety of fuels, including jet fuel, gasoline, diesel and Marine Diesel.

One of it's most notable features is the separate ammunition storage in a blow-out compartment for crew safety, which means that even if ammunition starts to cook off, flames and gas pressure energy will be released away from the crew and vehicle itself, while armored blast doors will contain them away from vehicle interior.

Ammo storage in this tank is 42 rounds total, 36 in turret bustle magazines (2 x 18 rounds) and 6 in hull magazine placed between turret and engine compartment. However because reload from the hull magazine to the turret magazines demands rotation of turret to proper position, and takes time, at the moment tanks in the mod can take only 36 rounds in total, which is also a practiced method by some real world crews. The main armament of the M1A1 is the M256A1 120 mm smoothbore gun, contrary to popular opinions it’s not the same as Rheinmetall Rh120/L44 120 mm smoothbore gun used in Leopard 2, but it’s based on the same technology, thus while both guns are not interchangeable, they have the same performance and can fire the same types of ammunition.

The ammunition types for the main gun are:

APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) M829, M829A1, M829A2 and M829A3.
HEAT (High Explosive Anti Tank) M830.
MPAT (Multi Purpose Anti Tank) M830A1.
HEOR (High Explosive Obstacle Reduction) M908.
HE (High Explosive) M1069.
Cannister M1028.

Inside the turret there's also a coaxial mounted M240. As a secondary weapons it has a M2HB/M2A1 Browning machine gun in front of the commander's hatch that can also be fired from within the tank and a M240 that is mounted in front of the loader's hatch on a skate mount. Coaxial M240 takes around 11400-12000 rounds of 7,62x51mm ammo in total, commander M2HB/M2A1 takes around 1000 12,7x99mm ammo, and loaders M240 takes around 400-800 7,62x51mm ammo.

Additionally a coaxial M2HB/M2A1 can be mounted above the main gun as a part of the TUSK upgrade kit. It takes around 400 12,7x99mm ammo in total.

M1A1FEP

Fire Control System

The FCS includes a rangefinder that can be activated with the key to lock target ( by default T ) and displays the distance to the target in the crosshair, if kept unmoved it will be locked in a second ( displaying a little square in front of the distance ). FCS can also calculate the lead for moving target, in such case player can notice that turret moves independently to gunners sight, this is when FCS induce lead.

Lead is the term used to refer to putting a gun in front of a target which is moving perpendicular to your vantage point. When you lead a target, you essentially need to fire in front of target at the point in which the round and target will meet.

Important to note is that when firing at stationary targets, it’s best to dump the lead ( by default G ) so any mouse movement will not cause the FCS to calculate lead and moving the turret, thus causing a miss. During movement it’s also best to not exceed speed of 45-50 km/h, because modern tanks FCS stabilization systems can keep up only up to this speed, otherwise FCS accuracy will drop significantly.

The rangefinder only works at distances from 200 meters to 5,000 meters for the main gun, and 200 meters to 1200 meters for coaxial machine gun.

The first image show a distance tracked and the second locked.

The key N switch to thermal vision, in positive and negative modes. Zoom can be activated with Num + and deactivate with Num -.

Optics

M1A1SA/FEP

Day channel – 3x and 10x zoom.
Thermal channel – 3x, 6x, 13x, 25x and 50x zoom.
Commander CWS sight have simple day sights.
CWS day sight – 3x zoom.
CWS unity sight – 1x zoom.

M1A1HC

Day channel – 3x and 10x zoom.
Thermal channel – 3x, 10x zoom.
Commander CWS sight have simple day sights.
CWS day sight – 3x zoom.
CWS unity sight – 1x zoom.