Source: WG
Internal test, Graf Zeppelin.
HE bombs now feature new circle drop pattern. It allows attacking from any angle with the same efficiency. However, ships with narrow hulls (destroyers and cruisers), will be receiving fewer hits, and it will take skilled manual attack to set several fires on a battleship.
AP bombs have more consistent penetration now, with 20 degrees normalization and drop angle improved from 75 to 90 degrees. The tradeoff is 5 seconds bomb flight time, which gives aware players some time for evasive maneuvers.
Secondaries range is decreased to 6250 meters in stock, but accuracy is improved by times. That means with AFT and Manual secondaries skills any target within 7500 meters range will receive consistent hits.
Update 0.6.9, Royal Navy battleships testing.
RN BB line features special main caliber AP shells fuse settings. Fuse delay is set to 0.15 seconds instead of regular 0.33 seconds. Fuse delay determines time of detonation after the shell is armed, and thus, it affects overall AP efficiency. AP shells with small fuse delay tend to detonate inside the target more often, causing less overpenetrations. This effect is mostly noticeable when firing at lightly armored and large-volume targets, like BB casemates and aircraft carriers. The same settings are already featured on Hood.
Update 0.6.9, Nelson battleship testing.
British tier VII battleship Nelson, which will become avaliable for 375 000 Free XP soon, features special Repair Party, just like Lion and Conqueror. Bonus 10% to bow, aft, casemate and superstructure repair, short work time, high repair speed (400% faster than regular BB version) and 2 charges in stock allow Nelson to tank and fight other battleships. According to current test results, these settings will be final.