My first post with some questions

[pdoktar]

HMG -Heavy Machine Gun
AAMG anti-air MG - targets both ground and air units
CMG co-axial MG - targets only ground units
SPAA - Self-propelled Anti-Air (Vehicle)
SPA - Self-propelled Artillery
MBT- Main Battle Tank
APC- Armored Personell Carrier
IFV / AIFV / MICV / ICV - different types on Infanty Fighting Vehicles, usually with autocannons and Anti-Tank Guided Weapons/Missiles (ATGM or ATGW)
RR - recoilless rifle, a low velocity gun, usually anti-tank firing HEAT rounds

Acc - The general accuracy of the gun
Kill - how effective at destroying infantry units
Pen - basic armor penetration capacity of the gun first digit for High Explosive (HE) round, second for Armor Piercing (AP) round
HEAT - penetration capacity of High Explosive Anti Tank round
APCR - Penetration capacity of Armor Piercing Capped Round (or sabot or other special Anti-Armour munition)
Generally bigger is better

If a round has enough penetration when it hits a vehicle, then it will penetrate it´s armor and do damage. For Example 120mm Gun with Pen 32 will penetrate at 0 metres tank armor of 31 and sometimes 32, but not usually armor of 35-50,(APCR might penetrate maybe 70-90 for such a gun). As the range increases, projectiles loose velocity and penetration power (HEAT ammo does not). Remember to check out both armor value and HEAT armor value for a given unit. Reactive armor works differently and will try to defeat a HEAT round before it touches the main armor under it. These armor and pen figures are estimates and corresponde with centimeters of Rolled Homogenous Armor calculations (Armor plate).

In the unit info screen you can click at a weapon system to activate and de-activate it.