Editing Tank (section)

===Offensive capabilities===
{{Main|Tank gun}}

[[File:105mm tank gun Rifling.jpg|thumb|upright| A sectioned 105mm [[rifling|rifled]] [[Royal Ordnance L7]] tank gun]]

The [[tank gun|main weapon]] of modern tanks is typically a single, large-[[caliber]] [[cannon]] mounted in a [[Gun laying|fully traversing]] (rotating) [[gun turret]]. The typical modern tank gun is a [[smoothbore]] weapon capable of firing a variety of ammunition, including [[armour-piercing]] [[kinetic energy penetrator]]s (KEP), also known as [[armour-piercing discarding sabot]] (APDS), and/or [[APFSDS|armour-piercing fin-stabilized discarding sabot]] (APFSDS) and [[high-explosive anti-tank]] (HEAT) [[shell (projectile)|shells]], and/or [[high-explosive squash head]] (HESH) and/or [[anti-tank guided missile]]s (ATGM) to destroy armoured targets, as well as [[High-explosive fragmentation|high-explosive]] (HE) [[High-explosive fragmentation|shells]] for shooting at "soft" targets (unarmoured vehicles or troops) or [[fortifications]]. [[Canister shot]] may be used in close or urban combat situations where the risk of hitting friendly forces with [[Shrapnel (fragment)|shrapnel]] from HE rounds is unacceptably high.<ref name = "USAToday2005b">[[#USAToday2005b|USA Today (2005)]], ''Tanks adapted for urban fights they once avoided''</ref>

A [[gyroscope]] is used to stabilise the main gun, allowing it to be effectively aimed and fired at the "short halt" or on the move. Modern tank guns are also commonly fitted with [[thermal insulation|insulating]] [[thermal sleeve]]s to reduce gun-barrel warping caused by uneven [[thermal expansion]], [[bore evacuator]]s to minimise gun firing fumes entering the crew compartment and sometimes [[muzzle brake]]s to minimise the effect of [[recoil]] on accuracy and [[rate of fire]].

[[File:German Leopard 2A6 from 3rd Panzer Battalion fires it's main gun during the shoot-off of Strong Europe Tank Challenge (40964003420) (cropped).jpg|left|thumb|German [[Leopard 2]]A6 from a Panzerbattalion fires its main gun during the shoot-off of [[Strong Europe Tank Challenge]].]]
[[File:Flickr - Israel Defense Forces - 188th Brigade Training Day, March 2008-cropped.jpg|thumb|left|A [[Merkava]] Mk IIID Baz firing]]
Traditionally, target detection relied on visual identification. This was accomplished from within the tank through [[telescope|telescopic]] [[periscope]]s; often, however, tank commanders would open up the hatch to view the outside surroundings, which improved situational awareness but incurred the penalty of vulnerability to sniper fire. Though several developments in target detection have taken place, these methods are still common practice. In the 2010s, more electronic target detection methods are available.

In some cases [[spotting rifle]]s were used to confirm proper trajectory and range to a target. These spotting rifles were mounted co-axially to the main gun, and fired [[tracer ammunition]] ballistically matched to the gun itself. The gunner would track the movement of the tracer round in flight, and upon impact with a hard surface, it would give off a flash and a puff of smoke, after which the main gun was immediately fired. However this slow method has been mostly superseded by [[laser rangefinder|laser rangefinding]] equipment.

Modern tanks also use sophisticated [[night vision device|light intensification]] and [[thermal imaging]] equipment to improve fighting capability at night, in poor weather and in smoke. The accuracy of modern tank guns is pushed to the mechanical limit by computerized [[fire-control system]]s. A fire-control system uses a laser rangefinder to determine the range to the target, a [[thermocouple]], [[anemometer]] and [[wind vane]] to correct for weather effects and a muzzle referencing system to correct for gun-barrel temperature, warping and wear. Two sightings of a target with the range-finder enable calculation of the target movement [[Vector (geometric)|vector]]. This information is combined with the known movement of the tank and the principles of [[External ballistics|ballistics]] to calculate the [[elevation (ballistics)|elevation]] and [[Aiming point|aim point]] that maximises the probability of hitting the target.

Usually, tanks carry smaller caliber armament for short-range defense where fire from the main weapon would be ineffective or wasteful, for example when engaging [[infantry]], [[Armoured car (military)|light vehicles]] or [[close air support]] aircraft. A typical complement of secondary weapons is a general-purpose machine gun mounted [[coaxial weapon|coaxially]] with the main gun, and a heavier [[anti-aircraft]]-capable machine gun on the turret roof. Some tanks also have a hull-mounted machine gun. These weapons are often modified variants of those used by infantry, and so use the same kinds of ammunition.