[RoaldLarsen]

Originally Posted by Draka

I simplified the designation quite a bit - I wanted the basics to be clear to the OP. As for HE vs AP, HE has an impact fuse and thus though it may cause a hole by the blast, it was not designed for such. AP was designed to make a hole as a primary purpose. This of course is very simplified - there are HE rounds with shaped charges, delayed fuze types of APC with secondary HE charges, etc - I really was trying to be basic and relate to in-game uses.

Agreed that HE have impact fuses and are therefore designed to explode as a result of impact.

Agreed that AP is designed to penetrate.

What I am disagreeing with is two statements:

HE - High Explosive - blast damage, good against crew and soft targets, but doesn't make holes (penetrate)

and

HE has an impact fuse and thus though it may cause a hole by the blast, it was not designed for such.

HE shells are intended to punch a hole and AP shells are intended to explode.

I may be wrong, but it is my understanding that the history of the develpment of naval ammunition goes something like this:

In the beginning there was shot: solid round cannonballs fired singly, or smaller shot fired in clusters(cannister and grapeshot) or non-ballistic shaped shot for damage to sails and rigging (chain). This was fired from a smooth-bore cannon. This was countered by iron cladding. This in turn was countered by a ballistically shaped ammunition fired from a rifled barrel and designed to penetrate iron cladding by virue of a much higher terminal velocity owing in part to its ballistic shape. Roughly at the same time as the development of rifled naval guns came the development of fuzed explosive ammunition. Earliest fuzes were time fuzes, but these were largely replaced by impact fuzes.

The purpose of this explosive ammunition was not to create a hole by means of explosion rather than impact, but rather to cause greater damage after impact. The shell would punch a hole in the cladding due to its mass and velocity, and then explode on the inside of the target. Both early rifled shot and explosive shell had similar ballistic properties and similar penetrative properties on impact. In practice, solid baliistic shot was rarely used, except in small calibre guns.

Rifled naval guns were countered by armour. This was specially forged or milled steel that was much harder than the iron cladding of early metal warhips and also much harder than the metal out of which merchant ships and smaller warships of the WWII era were made. The ammunition designed to defeat armour was AP. It differed from previous ammunition by having its point hardened or capped with a hard material and the case strengthened. In some cases it would also have a soft outer cap applied to improve ballistic properties so as to increase terminal velocity or improve accuracy. Again, most armour-piercing ammunition was a shell that contained an explosive charge and an impact fuse. Because of the need for a stronger case and a more complex tip, the explosive charge was smaller than in a simple explosive shell.

So, the difference between HE and AP shells was not that the HE was designed to go boom and the AP was designed to punch a hole. Both shells went boom and both shells punched holes. The difference was that the AP shell was designed to punch holes through harder surfaces than the HE. The design features that enabled this result in a smaller boom. HE was a simpler, cheaper shell that would go through the hulls or superstructures of most ships and then explode. AP was modified HE intended to defeat armour.

Naval HE shells were not designed to create a hole soley as a result of the explosion on impact. Do not confuse HE shells with shaped-charge anti tank ammunition such as HEAT (High Explosive Anti-Tank). Those wepons used the force of a directed explosion to defeat armour, rather than the kinetic energy of impact. To the best of my knowledge, nobody deployed naval ammunition in WWII designed to defeat armour through the force of an explosion.