Ammo

Virtually all ships offer a choice of ammunition.

Ammunition comes in three variants in World of Warships: high explosive (HE), armor piercing (AP) and semi-armor-piercing (SAP). Most ships with main battery guns have the option of firing HE or AP but tech-tree British cruisers only have AP shells, tech-tree Italian cruisers and Genova have SAP and AP shells, and Tier I cruisers only have HE shells. (Secondary guns fire only HE.) Understanding how the shell types behave and when to use them is a key to achieving optimum results in a battle.

Types

In flight, HE shells glow yellow, SAP shells glow red, and AP shells glow white. Shell colors are visible to other ships.

Selecting ammo type

On the battle screen, along the bottom, the ship's ammo types appear labeled [1] and [2] 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 [1] or [2] key for the desired type:

• If that type is already loaded, the key press does nothing.
• 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 use it. (The currently loaded ammo stays loaded for the next salvo.)

Pressing the key twice forces an immediate reload operation. The commander skill Expert Loader reduces the time for a forced reload by 50%, provided the guns are already loaded.

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Learn more about HE and AP shells.

Armor Piercing

Armor piercing (AP) shells rely on their kinetic energy alone to penetrate the armor. This makes the AP penetration model rather complicated, in contrast to the straightforward formula employed for high explosive (HE). The shell's kinetic energy depends on its impact velocity and mass. The impact velocity in turn not only depends on the initial (or muzzle) velocity but also on the target distance: shells lose speed in flight due to air drag (wind resistance), so AP shells have the less penetration capability the further they travel. This effect varies in strength for different calibers and different nations' shells. For example, the shells used by German heavy cruiser Yorck bleed off a lot of speed on the way, making them ineffectual above about half the maximum range. Additionally, AP penetration also depends on the angle of impact.

All of this means that armor piercing shells offer high damage potential, but are highly situational and require careful aiming and knowledge of enemy ship armor schemes to use consistently. When firing AP at a target in the game, four things can happen:

1. The shell strikes heavily angled armor and ricochets.
2. The shell hits un-angled armor, but still fails to penetrate and shatters.
3. The shell over penetrates the enemy ship by striking armor that is too thin to arm the fuse and deals 10% of its listed damage.
4. The shell hits armor thick enough to arm the fuse and penetrates, doing 33% of the listed damage, or 100% if it penetrates the citadel.

It is entirely possible to have all four happen to individual shells in one salvo. There is also the peculiarity of a single shell doing all three forms of damage (10%, 33% and 100%) simultaneously.

Simply put, AP shells do more damage, but require careful aiming to achieve penetrations, while HE shells do less direct damage, but do light fires and ignore angling.

When to Use AP

A 4,000 damage AP salvo from a destroyer on a Yamato at mid-range. Note the penetration ribbons on the right.

Armor piercing shells do damage by penetrating the target and then detonating inside the ship. AP requires, in general, to hit a sufficiently thin section of armor at a nearly right angle. As such, AP is most effective against broadside targets and weakly armored target sections.

Battleships should be firing AP at most targets, as their large caliber and high penetration allows them to usually do damage upon successful hits. Aiming for the waterline on most targets should be fine, but some heavily armored battleships have belt armor thick enough to bounce other battleship AP shells, so aiming above the main belt will work better.

Cruisers should fire AP when presented with an almost completely broadside target. Cruiser guns have significantly lower penetration than a battleship guns, so more careful aiming is required to hit lightly armored sections of armor. A good rule of thumb is to aim for the armor belt just below the deck line on most battleships, and at the waterline for other cruisers and aircraft carriers at close range.

Destroyers do not normally fire AP, but if presented with a perfect broadside at close range, regardless of the target's class, they should load AP. Even the 100mm guns of Akizuki are capable of landing a couple thousand damage AP salvos on a broadside battleship (particularly the superstructure). Destroyers can also use AP against other broadside destroyers, but if there is a lack of damage HE is probably the better choice.

High Explosive

High explosive (HE) rounds, like AP, require penetration to do damage. However, unlike AP, HE ignores armor angling and cannot over-penetrate a target (although it can still citadel). High explosive rounds will do 0 damage on shatters, 33% damage on penetrations, and 100% damage on citadel penetrations. HE penetration can be calculated for most ships by dividing the shell diameter by 6 and rounding to the nearest whole number. The HE shell can penetrate armor up to, but not including, the calculated value.

For British battleships, German battleships, German cruisers, and Japanese 100mm guns, the HE penetration is calculated by dividing the shell diameter by 4 instead.

Example

• The Tier VIII Japanese cruiser Mogami has a stock gun diameter of 155 mm. Using the Shell Diameter/6 rule, we get a value of 25.83 mm, or 26 mm. This would allow Mogami’s HE shells to penetrate armor sections up to, but not including, 26mm at any angle.
• The 203 mm guns found on Tier VIII German cruiser Admiral Hipper have an HE penetration of 203/4 = 50.75mm = 51mm.

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Learn more about high explosive shells.

Inertia Fuse for High Explosive

HE penetration can be increased through the use of the Level 4 commander skill Inertia Fuse for High Explosive, which increases the penetration by 30%. This is useful for allowing light cruisers with 150-180mm guns to achieve over 32mm of penetration with their HE rounds, allowing them to damage the bow, stern, and superstructure of most high tier battleships more consistently.

Example

Using our two previous examples and multiplying the penetration by 1.3:

• Mogami: 25.83 * 1.3 = 33.58 = 34mm
• Admiral Hipper: 50.75 * 1.3 = 65.975 = 66mm

Note: IFHE is calculated before rounding occurs.

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More tips on when to use each type of shell.

When to Use HE

HE should be used when firing at an angled heavily armored target, or when firing at a lightly armored target. HE in almost all cases 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 on enemy ships to allow a friendly carrier to strike them easier.

Battleships should only fire HE at another angled battleship at range. Their AP damage is consistent enough that the HE is usually not worth using. Against destroyers, the question of HE vs. AP largely depends on the situation. A battleship that is GUARANTEED to get a shot on a destroyer should consider spending the 15-30 seconds to reload HE. Captains that need to quickly fire a shot off while a destroyer is spotted, however, should fire whatever shell type is loaded.

Cruisers primarily fire HE. Their AP simply doesn't have the penetration required to get consistent damage on non-broadside targets, so HE is the go-to shell type. Furthermore, a cruiser's rate of fire allows them to rapidly light and re-light fires on multiple targets to stack significant fire damage. Cruisers should also fire HE against destroyers (except in rare cases, such as Tier X Russian destroyer Khabarovsk).

Destroyers, like cruisers, primarily fire HE at every target, unless they present broadside. Keep in mind that many destroyers' primary source of damage is torpedoes, and they should limit main battery usage to avoid detection.

Fires

Fires are the primary form of damage over time in World of Warships (the other being flooding), and is a vital source of damage for most cruisers and some destroyers.

High explosive shells have an attributed fire chance to them; however, it is important to note that higher tier ships have greater built-in fire resistance that reduces this fire chance. The fire chance of main battery and secondary battery shells can be increased through the use of signal flags and commander skills.

Semi-Armor-Piercing

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Semi-armor-piercing (SAP) shells combine the features of both AP and HE shells.

• SAP shells may ricochet after hitting their target, but they have quite favorable ricochet angles — even better than those of the AP shells fired by British and American cruisers:
  • Shells fired by II Nino Bixio have a chance of ricocheting at angles of 80 degrees or higher, and are guaranteed to ricochet at angles of 85 degrees or higher.
  • Shells fired by any Tier III–IX ships have a chance of ricocheting at angles of 70 degrees or higher, and are guaranteed to ricochet at angles of 80 degrees or higher.
  • Shells fired by X Venezia have a chance of ricocheting at angles of 75 degrees or higher, and are guaranteed to ricochet at angles of 80 degrees or higher.
• If your hit doesn't ricochet, the armor penetration mechanics are similar to those of HE shells: the thickness of the armor at the point of impact is compared with the shell penetration value. The shell deals damage if the penetration value is higher than, or equal to the thickness of the armor.
• SAP shells can penetrate thicker armor and cause greater damage than HE shells. The exact penetration value depends on the shell’s caliber, and the damage is determined by the shell's caliber and speed.
• They can't overpenetrate targets.
• They can't start fires on enemy ships.
• SAP shells have no limit in terms of the damage they can cause to destroyers.

When to Use SAP

Before choosing which shell type to use for your attack, consider your target. SAP shells are most efficient against destroyers, battleships, and angled cruisers. AP shells perform better against any cruisers that leave their broadsides exposed. If an enemy ship is positioned at an angle to you, prefer SAP shells: when hitting the ship's front or aft ends and superstructures, they can deal impressive damage. However, the heavy damage they can cause is offset by their inability to set fires on enemy ships. Choosing the right shell for each situation and evaluating the target's armor are vital skills to learn when mastering the Italian cruisers' gameplay.