The effective range of a weapon is the range at which it will have a specific type of effect on a particular target. It is distinct from the weapon's absolute maximum range, which is the furthest it can throw a projectile in accordance with the laws of physics, and is only normally used for large artillery guns. As an example, the absolute maximum range of a Beretta M9 (aiming it up in the air like a mortar) is 1,800 meters, while its effective range on a point target is just 50 meters.
There are four main types of effective range figure:
Absolute maximum effective range Edit
This is the distance at which the energy of a round drops to the point where it can no longer be considered lethal: there is no accuracy requirement attached to it. It is sometimes quoted misleadingly in PR materials: for example, this is the range figure used in claims that the FN P90 is "effective" against unarmored targets at a range of 400 meters.
Maximum effective range on a point target Edit
This is the range at which a weapon can hit a target, typically one the size of a human torso for smallarms and one the size of a tank's hull for anti-tank weapons, with 50% of shots fired, when secured in a machine rest. It does not require the round to retain lethal energy at this range: if it does not, the absolute maximum effective range figure tends to be used instead.
Maximum effective range on an area target Edit
Typically used for machine guns, this is the range at which a weapon lands 50% of shots inside an area of defined radius, hence the very high effective range figures for machine guns even compared to rifles firing the same caliber. As with range on a point target, it does not require the round to retain lethal energy at this range: if it does not, the absolute maximum effective range figure tends to be used instead.
Sniper rifle effective range Edit
The range at which an expert marksman can be expected to achieve a guaranteed hit on a human-sized target.