Japanese 12" Gun

[John 3rd]

Hello.

I've been looking around for the B-64 Battlecruiser that was to mount 12" Guns. Does anyone have the statistics for those guns?

[el cid again]

No statistics have been found for the 50 cal gun intended for triple mounts in the projected battlecruisers
795 and 796. It seems most likely that it would have been 310 mm (12.2 in) bore rather than 304.6 mm (12 in).
A number of the latter guns in twin turrets were removed from ships scrapped under the Washington treaty were
mounted for coast defense.

Naval Weapons of World War Two by John Campbell p. 185

[el cid again]

A comparable modern gun was the US Mark 8 intended for the Alaska class.
Actual bore 304.8 mm. Range 38,573 yards (35,271 meters). These were 49.7
calibers (very similar to the Japanese 50 caliber intention). The firing
cycle was 20 to 25 seconds corresponding to a rate of fire of 3 per minute
at the maximum end, only 2.4 per minute at long range (due to the time
needed to lower the gun, load, then re-elevate it to achieve the range).
This gun fired a 1140 pound shell (517 kg).

Japan used 250 mm turret face armor on its 14 inch guns of an earlier vintage.
The problem with a smaller ship is that is a lot of weight so high up on the
hull - so it represents about the maximum possible. The rear was 230 mm and
the roof 150 mm.

By comparison Japanese cruisers were almost unarmored - 25 mm facings on every
type except the tiny training cruisers (Katori class) which had 50 mm! Note
that the battlecruisers were not in fact battlecruisers (intended to stand in
the line vs battleships) and may well have adopted a much lower standard of
turret armor (the 50 mm of Katori seems reasonable). Japanese guns were also
not very fast on the firing cycle. The eight inch cruiser guns could fire at
3 rounds per minute at best - two at long range (20-30 seconds). The BC would
have been no better and likely not as good - perhaps 2.5 per minute - but
2 was a world standard for heavy guns for a long time - so it would not be less
than that. It is your mod - you need to make your own statistics for a gun whose
data was not preserved. But it WAS built and tested. There were also turrets
built for the first ship. So it isn't quite fictional.

[Admiral DadMan]

31 cm/50 (12.2") Type 0

[RedTaurus]

ORIGINAL: John 3rd

Hello.

I've been looking around for the B-64 Battlecruiser that was to mount 12" Guns. Does anyone have the statistics for those guns?

Does this help? http://www.navweaps.com/Weapons/WNJAP_Main.php

RT