There are three types of loadable ammunition in World of Warships: high explosive (HE), armor piercing (AP) and semi-armor piercing (SAP).
Understanding how the shell types behave and when to use them is important to achieving optimum results in battle. This article focuses on which ammo to select in a given situation. For details of how the types work, please see the dedicated article Armor Penetration.
- 1 HE shells
- 2 SAP shells
- 3 AP shells
- 4 Selecting ammo type
- 5 Which type to use?
- 6 Guns and their shell types
- 7 Torpedoes
- 8 Airborne Ordnance
- 9 Notes
There are three main parts to a shell: a casing, an explosive charge, and a fuse to set off the charge. Varying these components changes how the shell performs when it smacks into something hard.
High Explosive (HE) shells have a relatively light casing, are packed with high explosive, and are fused to explode on contact. They are not expected to punch through heavy armor but to create a blast volume of concussion, flame, and fragments, perhaps penetrating structure or light armor and wrecking things like modules within the blast volume. They also start fires.
The performance of an HE shell is determined by two things: the caliber of the shell (and thus the amount of high explosive it contains), and certain national attributes (e.g. IJN HE will do more damage than other nations, and KM HE less.) In summary, HE shells:
- can penetrate light armor for direct ship damage;
- do not ricochet;
- do not overpenetrate;
- do produce Shatter ribbons, but these are No Penetration hits that may well do blast damage;
- explode on contact (with anything) creating a blast volume in which lightly armored modules can be damaged or destroyed, even if the shell does not hit the ship itself;
- can start fires;
- glow yellow in flight.
Direct damage to the ship is inflicted only if the shell penetrates the part of the ship it hits. Blast damage and fire may be inflicted whether or not it penetrates. Modules protected by 76mm or thicker armor are immune from blast damage so larger main gun turrets are safe, but most if not all secondary and AA batteries and torpedo launchers are vulnerable, as are engines and steering gear. A blast might even ignite a magazine.
HE shells can be used in different ways, depending on the target. For a very lightly armored target like a destroyer, AP can simply blow right through it without fusing, doing little damage, while HE will always explode and usually penetrate. For a very heavily armored or angled target, incapacitating modules can be important but setting fires is the main purpose of HE. While the penetration damage of a light cruiser's HE might be negligible, multiple and repeated fires are a real danger even to behemoths such as Yamato.
The IFHE skill
The commander skill Inertia Fuse for HE Shells increases HE penetration by 25% at the expense of a halved base fire chance (the additional fire chance of signals and skills is not halved). This skill enables cruisers to penetrate the plating of battleships of the same tier but at the cost of fire chance. It is best used on ships which can both penetrate common armor thresholds with the additional penetration and have low base fire chance.
Example The Tier VIII cruiser Cleveland has a stock shell diameter (caliber) of 152 mm. The Caliber/5 rule yields a value of 30.4 mm. Without the skill an HE shell from Cleveland can penetrate 30 mm armor, from any angle.
Now the commander acquires the IFHE skill. 30 * 1.25 = 37.5, rounded down to 37. An HE shell from Cleveland now can penetrate 37 mm armor, from any angle. Her shells also lose half their base fire chance.
Semi-armor-piercing (SAP) shells combine the features of both AP and HE shells. The nose of the casing is thickened to form a penetrator cap, of a sort, with less high explosive than HE but more than AP shells can pack in. SAP is fused to explode on impact.
Like HE shells, SAP armor penetration is not a function of shell velocity or angle of incidence. Penetration depends on the caliber of the shell and the nominal thickness of the armor. The shell penetrates and deals damage if the penetration value is higher than or equal to the thickness of the armor. The value for each caliber appears in the chart below.
- often have a higher maximum damage than the gun's AP;
- can ricochet but have very favorable ricochet angles — even better than those of American and British AP;
- can penetrate thicker armor and cause greater damage than HE shells;
- cannot penetrate multi-layer armor;
- do not overpenetrate;
- do not generate a blast capable of damaging modules;
- do not start fires;
- do not have the damage limit against destroyers of some AP;
- are not affected by the IFHE skill;
- glow red in flight.
SAP vs. AP Characteristics
|Tier||Ship||Bounce angle||Max. Damage||Muzzle Velocity||Pen. (mm)||Bounce angle||Max. Damage||Muzzle Velocity|
|203/50||V, VI||Genova, Trento||70°-80°||4860||840||54||45°||4700||840|
|203/53||VII, VII||Gorizia, Zara||70°-80°||5050||900||54||45°||4800||900|
Armor Piercing (AP) shells trade some explosive for the ability to punch through armor. The nose of the casing is a pointed, high-density metal cap that, at least in theory, forces its way through armor plate. Because of the mass of the penetrator (the metal cap) a smaller amount of high explosive can be carried. An AP shell carries a time-after-impact fuse, to provide a short time (typically 0.033 sec) for the shell to penetrate before exploding.
The intention of the design is that an explosion inside a critical (and thus well-protected) area of the target ship is more effective than a larger explosions in a less critical area. AP shells carry out that intent well — in the right situations. Other characteristics of AP shells:
- can shatter;
- can ricochet;
- can penetrate heavy armor in the right circumstances;
- can overpenetrate;
- can damage or destroy modules by direct hit;
- do not start fires;
- glow white in flight.
The interaction of Armor-Piercing shells and heavy armor is quite complex. See the dedicated article Armor Penetration for details.
Before the first Iowa-class USN battleship was laid down, the US Navy developed the "super-heavy" 1,225 kg Mark 8 shell for its new 16" Mk.7 gun. This shell is deployed on all Tier VIII+ USN battleships for their 406mm/45 Mk.6 and 406mm/50 Mk.7, and in a larger variant (1746 kg) for their 457mm/45 Mk.1 guns.
Employing the same technology, the US Navy developed super-heavy AP (SHS) shells for its heavy cruisers. All Tier VIII+ USN cruisers (except Wichita and Anchorage) mounting 203mm/55 Mk.15, 203mm/55 Mk.16, and 305mm/50 Mk.8 guns fire SHS AP shells (152 kg and 517 kg respectively).
The secret to SHS AP performance is the heavier shell weight. The kinetic energy of a shell (or anything) is Ek = (mass x velocity). With the same initial (muzzle) velocity, a shell with more mass will have more energy. As a shell travels through the air, it loses energy to drag, slowing it down. The amount of drag is essentially the same for both heavy and light shells. Thus at the point of impact the heavier shell will have more of its energy left. This extra energy translates directly into better armor penetration, along with a little extra range.
In battle, SHS is functionally identical to 'normal' AP. It just hits harder.
Selecting ammo type
On the battle screen, along the bottom, the ship's ammo types appear labeled  and  with a picture of the shell above.
The HE shellhas a yellow nose and stripe. SAPhas an unpainted nose and a thin red stripe. APhas a red nose and red stripe.
To select ammo type, press the  or  key for the desired type:
- Switches to gun aiming view from such as the torpedo aiming view.
- If the selected type is already loaded, the key press does nothing else.
- If a different ammo is loading (not yet fully loaded), that load operation stops and loading of the new type starts.
- If a different ammo is loaded, the next load will be of the selected type. (The currently loaded ammo stays loaded for the next salvo.)
Pressing the key twice forces an immediate reload operation. The commander skill Gun Feeder reduces the time for a forced reload by 50%, provided the guns are already loaded.
Which type to use?
The simplest answer is, "Load HE or SAP against ships facing toward or away from you; load AP against ships turned broadside to you."
Of course, the best answer is not that simple. There are a number of factors that influence the right ammunition choice for your situation:
- the caliber of your guns;
- the nature of your shells;
- the type of target ship, it's range and armor scheme;
- the target ship's orientation to you and how it is maneuvering;
- what you currently have loaded or loading.
Armor-Piercing shells do their maximum damage by penetrating the target and detonating inside the ship. To assure penetration, AP must hit at a nearly right angle. It is most effective against broadside targets and weakly armored target sections.
High Explosive should be used when firing at an angled heavily armored target, or when firing at a lightly armored target. HE should be aimed at the targets superstructure or bow and stern sections. HE can also be used in a strategic fashion to destroy anti-aircraft guns to decrease the danger to friendly aircraft.
SAP acts much like HE without the threat of fire or module damage. Since the alternative is AP, the decision to use it is very much like that of choosing between HE and AP.
Some battleships, notably Conqueror, have HE with a very high fire chance. The commander may prefer to load HE, but he should remember that AP in the right circumstance is the more deadly option.
Destroyers have no citadel. Compared to what battleship AP is designed to damage, they are unarmored. Battleship AP should not fuse on destroyer armor so hits (probably overpens) are limited to 1000 HP damage. Against DDs, a BB with the option should load HE.
Don't ignore cruiser AP, though. Even 6" AP from such CLs as Dallas can be devastating to other cruisers, especially at close range.Akizuki are capable of landing a couple thousand damage AP salvos on a broadside battleship (particularly the superstructure).
The larger question for destroyer captains is whether to fire at all. In many ways, a destroyer's stealth is a greater weapon than its guns.
Guns and their shell types
- Most ships can fire HE or AP shells.
- Tier I cruisers can fire only HE shells.
- Tech-tree II-X British light cruisers and special cruiser X Plymouth can fire only AP shells.
- Tech-tree II-X Italian cruisers, premium cruisers V Genova and VII Gorizia and tech-tree Italian battleships can fire SAP or AP shells.
- Italian premium destroyer IX Paolo Emilio can fire HE or SAP shells.
Secondary guns usually fire HE shells.
- For the HE penetration rules, see Armor Penetration,
- SAP is currently (0.8.11) deployed only on Italian ships.
- New type of Shell article.
- Between the listed angles, there is an increasing chance that the shell will ricochet.
- Penetration = ((0.24908 x caliber) + 4.37966) rounded down.
- Between the stated angle and 60° there is a chance that the shell will ricochet.
- Paolo Emilio fires HE instead of AP shells.
- For comparison, a light (862 kg) 16" HE shell is fired at 820 m/s. The heavy (1,225 kg) Mk.8 SHS AP shell is fired at 762 m/s. Even though initially slower, the heavy projectile possesses 355 Mega-joules energy while the light projectile possesses 290 Megajoules.
- Since British cruisers have only AP, it appears labeled . Pressing  or  has no effect on ammo type but switches to the gun aiming view from such as the torpedo aiming view.