Recently on the unofficial discord a user shared an instance of a big heavy cruiser with 1.5" D armour being destroyed by a 6" HE D* magazine hit. I was surprised because, while HE magazine hits were something I saw quite a bit in RtW2 I haven't seen them in 3, until now.
I went to see if I could replicate the event with some of my own 6" cruisers with 1" deck armour and, sure enough, on the first attempt 1 of the 4 cruisers I took to an all HE fleet ex went up to an HE D* hit.
I then went to a super large USA 1920 start and did some all HE fleet exs with all the capital ships and across 3 exercises I had 2 ships explode to HE D* hits. So, while the hit isn't particularly common, it's not a freak event either provided ships are actually firing HE. I think this sort of magazine hit would be impossible, or nearly so.
I appreciate an HE shell that detonates in contact with armour could absolutely blow holes or cause spalling and lead to significant damage in the space behind the plate (this is a major danger to turret tops as was seen in the firing trials on Baden where a 15" CPC shell made a big hole in her 4" turret top at an impact angle where the AP shell was unable to penetrate). However, to actually reach the main armour deck a shell is going to have to travel deep into the ship and I think an HE shell, especially a smaller one, ought to explode before it gets that far. With WWI style armour schemes the shell would usually have to penetrate some other armour before reaching the lower armour deck instead of just hull plating which should certainly set off an HE shell that isn't a dud. Further, on a lot of AoN ships the magazines are well below the armour deck and might well have additional splinter protection which would protect the magazine from a contact explosion on the armour deck that sends hot fragments further below.
I also noticed a bunch of HE * hits against heavy vertical armour. For example in one fleet ex this ship
- oregon.png (16.25 KiB) Viewed 164 times
The reported penetration of 12" AP at this point is only 11.6" at 10,000 yards. For the 14" it is 15" at 8,000 yards. In other words, HE shells are getting * hits against roughly calibre thickness armour at ranges where AP shells would be around the limits of their expected ability to penetrate. I get the * is supposed to denote spalling or other through armour effect as well as full penetrations but this still seems like a lot out of HE, certainly more than I'd expect from the 40% calibre thickness William mentioned on the NWS forums a while back
As an aside it would be cool if full penetrations were denoted differently from partials/though armour effects in the logs, ** as opposed to just * maybe.
