![Prototype 406mm Twin Cannon Mk4 [T0]](https://pasokau.com/wp-content/uploads/soubisamu/senkan23.jpg)
This page summarizes the stats and overall evaluation of the battleship main gun "Prototype 406mm Twin Cannon Mk4 [T0]" appearing in Azur Lane.
Video commentary is also recommended!
Stats
Stats of Battleship Main Gun "Prototype 406mm Twin Cannon Mk4 [T0]" (Enhancement +10).
Prototype 406mm Twin Cannon Mk4 [T0]
Main gun damage of equipped battleships increases by 10%; reload time for your own main gun attacks from the 5th onwards increases by 35%.
Armament Development
Enhancement +13 grants 130% bonus
Common Name: Mk4
Overall Evaluation
Overall evaluation of the battleship main gun "Prototype 406mm Twin Cannon Mk4 [T0]."
Rating: ★★★★★
Armor-Piercing
Battleship main gun AP shells are strong against medium and heavy armor.
Superior muzzle velocity compared to HE shells.
When hitting enemies with heavy armor, there is a 20% chance to put the enemy into an armor-shredded state. Enemies in an armor-shredded state take 8% more damage from artillery for 6 seconds.
Basic Performance
The Mk4 is a twin cannon with AP shell attributes.
Its projectile range is narrower than other twin cannons,
and it features superior muzzle velocity compared to the Champagne cannon.
Due to these characteristics, its accuracy against stationary enemies is high, allowing for full hits.
Power 166x2 shots, bonus 110%, higher anti-armor multiplier for medium and heavy armor than normal AP main guns, with a 10% main gun damage increase. This is an amazing item with an attack speed under 19 seconds.
For reference, the [380mmSKC Twin Cannon [T3]] obtainable from the equipment box has a power of 132x2 shots, a bonus of 110%, an anti-armor multiplier of 45/130/110, and an attack speed of 18.38s. The Mk4 is only slightly slower, but gains superior attack power and accuracy.
The downside is that after the 4th main gun attack, the main gun reload is extended by 35% until the end of battle. The 10% main gun damage increase remains.
Ideally, the battle should be decided before firing the 5th main gun shot. However, it fits within the 90-second time limit, allowing for up to 4 normal reloads + 1 extended reload = 5 attacks.
Disadvantages
The disadvantage of the Mk4 is triggered by the number of main gun attacks. Therefore, for ships that can use their main guns at the start of battle, or ships like Gascony with many main gun attacks, the reload extension will activate earlier than usual.
Normal: 4 attacks, then extended
Opening Main Gun: Opening + 3 attacks, then extended
Gascony: 2 attacks + 2 attacks, then extended
AP Shell Comparison
Monarch's Main Gun DPS
The Mk4's medium armor DPS is high enough to rival rainbow AP shells.
Monarch Main Gun + Special Barrage 70%
The Mk4 pairs well with battleships that can unleash powerful special barrages upon firing their main guns.
Monarch Main Gun + Special Barrage Damage
Compared to rainbow AP shells, the total damage is about 8% less against medium armor and about 10% less against heavy armor. For gold equipment, this difference is acceptable, making it a viable alternative to a second rainbow AP shell.
Furthermore, the Mk4's main gun reload is 1.4 seconds faster than rainbow AP shells and 4 seconds faster than the Champagne cannon. In situations where the Mk4 can perform one more attack, it can outperform the others.
Especially when aiming for 3 attacks with Champagne's barrage, Mk4 can achieve 4 attacks with a slight delay. In this case, if there are no other conditions, Mk4 can be considered advantageous.
Enhancement +13
Mk4 is a gold equipment, so it can be enhanced to +13 with 120 T4 parts. Even if the same amount of T4 parts are used for Rainbow AP Shells, it will only reach +11. Let's compare their performance under these conditions.
Monarch's Main Gun + Special Barrage Damage
The difference between Mk4 and Rainbow AP Shells is small, with a total damage difference of about 2% against medium armor and about 4% against heavy armor.
Additionally, although slight, the difference in "Siren Operation Bonus" can also be utilized in Siren Operations.
Given the advantages of accuracy and attack speed, enhancing Mk4 to +13 is a viable option.
Ammunition Penalty
Mk4's main gun damage increase effect belongs to the "damage dealt increase" category.
It is added to the ammunition correction, so even in battles with 0 ammunition, Mk4's main gun damage alone can be fought at 60% (normally 50%). Under these conditions, the damage difference with Rainbow AP Shells is small, and either choice seems fine.
Furthermore, depending on the combination, you can fight without worrying much about the ammunition penalty. Mk4 might be useful in situations like fighting 6 battles in one fleet or achieving all enemy destruction.
Overall Evaluation
Mk4 is an AP shell main gun that excels in firepower, accuracy, and attack speed. While its raw firepower is inferior to Rainbow AP Shells, its other stats are high, and depending on the situation, Mk4 may be prioritized over other AP shells.
The drawback is that it doesn't sync well with skills that activate every 20 seconds. Even Helena Kai equipped with SG Radar will have its cycle misaligned from the second activation.
However, recently, there has been an increase in ally support skills that activate every 15 seconds, making Mk4 the optimal main gun when paired with them. Depending on future developments, the value of Mk4 could increase further.
Compatible Ships
Ships that pair well with the battleship main gun "Prototype 406mm Twin炮Mk4[T0]."
Attack Order
Mk4's superior attack speed makes it useful for adjusting the attack order.
It pairs well with Duke of York, who prefers to attack first.
Special Barrage
It pairs well with ships whose powerful special barrage skills activate upon main gun attacks.
Monarch's special barrage also has a slowing effect, making it a good match with Mk4, which can attack first.
Reload Reduction
It's possible to increase the number of attacks per battle by combining it with opening main gun attacks or reload reduction skills.
For example, Champagne has a 15% reload boost and a 40% reload reduction, completing the reload in about 9 seconds. With the opening main gun attack, she can perform 4 attacks in about 30 seconds.
Additionally, Little Renown has a 40% reload reduction until the third time, completing the reload in about 10 seconds.
It might be useful in short, consecutive battles along the way.
Ammunition Penalty Reduction
Marco Polo and
Bismarck (Proof of Promise) are battleships and can reduce the ammunition penalty by 15%. Combined with Mk4's damage increase, they maintain 75% of their main gun damage even in battles with 0 ammunition. If both ships are used together, Marco Polo alone reaches 90%.
If you deploy Gloucester in the vanguard, other battleships can also maintain 75%.
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