Before you go into combat, you should have your tank fully loaded with ammunition; if your tank is loaded with too few rounds for the match, a warning will pop up. Be careful not to click past it. The amount of ammunition that each tank can carry depends on the gun caliber and the turret, which is listed in the in-game specification pages for each tank. The ammunition you choose will affect your combat performance. Below are brief descriptions of each shell type in the game. Premium ammunition can be optionally purchased for credits at the standard gold-to-credit conversion rate of 1:400 by pressing the price of the round in the ammo loading screen. In other words, a premium shell that costs 10 gold will cost 4000 credits.
Premium ammo is frequently nicknamed "prammo," "gold rounds," or simply "gold." On a more comical note, players that primarily use premium ammunition in battle are derogatorily called "gold spammers" or "gold noobs."
The damage value listed in the ammunition's description will vary within the listed range; for example, if the damage values say "300-500," the damage done by a penetrating AP round will be between 300 and 500 HP.
Armor Piercing (AP) Shell
This shell does the damage listed in the gun and ammunition specifications if it penetrates the enemy's armor. However, if the shell does not penetrate the target, it will not do any damage. It can also damage tank modules and crew members. AP shells have 5 degrees of normalization, and lose some penetration at over 100 meters. This will differ from gun to gun. The AP shells are the default shell type on most tanks except weapons that fire APCR and HEAT and tanks with howitzer type guns.
Armor Piercing Composite Rigid (APCR) Shell
APCR ammunition as a premium shell will have higher penetration values than AP, but loses 15% of the damage. It has 2 degrees of normalization. This means that it is more effective against angled targets than HEAT ammunition, but not as effective as AP for angled targets because of the lower normalization values. APCR has a higher muzzle velocity than AP, meaning that a shell leaves your gun at a higher speed, making it easier to hit moving targets at long distances. APCR loses more penetration value over the same distance as AP.
Some tanks, such as the all tier 10 mediums, Centurion 7/1, the IS-3 Defender, IS-6, IS-5, IS-2sh and the E25 will fire APCR as its default ammunition, replacing AP. APCR used in place of AP rounds will not cost gold or a large sum of credits to purchase, while still featuring the standard characteristics of APCR ammunition, with the added benefit of the same penetration loss over distance as AP. Tanks with this option will have HEAT and HE or HESH as their second and third type of ammunition.
High Explosive (HE) Shell
This shell has the highest damage value among all the shell types in the game, but it generally has very low penetration values. These rounds have a splash damage area, making it possible to damage multiple enemy vehicles within close proximity of each other. Unlike the other ammunition types, HE does not need to penetrate to damage the target, but the damage drops off quickly as the difference between the target's armor and the shell's penetration value increases. If it manages to penetrate the armor, it will explode inside the tank for the damage listed in the specifications. Additionally, HE rounds can deal damage to multiple internal modules and/or crew. Given these characteristics, High Explosive shells are VERY useful for damaging modules, or for getting guaranteed (or more likely) chance of damage on a heavily armored/low HP vehicles.
You should also be careful firing high caliber (122, 128, 152, 183) HE shells at point blank, as the splash may damage you.
If any "High Explosive" shell hits an obstacle (Cars, Fences) it will explode on impact, therefore not hitting the enemy.
Some tanks, such as the RU 251 have a special HE shell usually referred to as "High Explosive Plastic" in the US, where the penetration values on the HE are much higher than regular HE but also much lower penetration than HESH. These shells appear identical to HE in the game and cost the same, but can be spotted by looking at the penetration values, which are usually about two and a half times the regular HE penetration of the gun's caliber.
High Explosive Anti-Tank (HEAT) Shell
This ammunition type has a higher penetration value than AP, but unlike APCR, HEAT does not have normalization, and therefore must penetrate the effective armor value at the given impact angle. As a result, HEAT rounds will have more trouble dealing with very sloped, and/or spaced armor when compared to the other ammunition types. This also means that shells that hit the tracks are likely to be absorbed, dealing no damage to the enemy tank. However, also unlike AP and APCR, HEAT does not lose penetration value over distance. HEAT usually has a slower muzzle velocity than AP and APCR, similar to HE. Users should be aware that HEAT, like AP, will bounce off if it does not penetrate the armor of a target. In addition, HEAT, being a premium ammunition, will generally have 15% less damage than standard AP (except in cases where HEAT is the standard ammunition, such as in the Vindicator and the T49's 152 mm Launcher).\
Penetration mechanics through spaced armor are as follows. When the HEAT round strikes the spaced armor, it instantly loses the thickness of the spaced armor in pen. After that, every 100mm between the spaced armor and the primary armor, the HEAT shell will lose 5% of its penetration.
HEAT shells can be identified by their orange trail, and a “Clanging” and “Hissing” sound when it hits a tank
If any "High Explosive" shell hits an obstacle (Cars, Fences) it will explode on impact.
High Explosive Squash Head (HESH) Shell (HE)
This shell has similar functions as an HE shell, but with comparatively higher penetration values. If a HESH round does not penetrate, it still behaves in the same way - it will explode on the surface of the armor, dealing some damage to the enemy. It will lose damage as the difference between the penetration value and armor thickness increases.
HESH is used as the premium ammunition on several high-tier British tanks. They also use HESH as what would normally be regular HE, but this HESH has greatly reduced penetration compared to the premium variant. Though not directly stated as HESH ammunition, the high explosive ammo for the 120mm L1A1 gun on the Conqueror and FV215B are in fact HESH, as they have double the penetration of regular HE ammunition on similar caliber guns. This type of ammunition is only available for British tanks.
In Patch 4.0 The FV4202 and Centurion 7/1 Premium ammunition was changed to HEAT due to “Underuse” The devs claim that HESH will soon return to the 105mm Royal Ordanance L7A1 weapons
In Patch 4.1 the FV4202 and Centurion 7/1 gained a second premium ammunition at the cost of regular HE shells: From the patchnotes: The HESH-T L-37 shell for the 105 mm Royal Ordnance L7A1 gun installed in the Centurion Mk7/1 and FV4202 was replaced with a Premium HE-shell HESH-T L-37. Changed the shell price in Gold (10 Gold). The shell penetration increased to 210 mm.