A question about the USN 8"/55 Mk.14

[Phoenix_jz]

Hello all; just a quickie here.

 

Does anyone have a source that states the USN 8"/55 Mk.14 fired it's HE at 823mps (2700 ft/s)?

 

I've been looking, but I've only ever seen 853mps (2800 ft/s) referenced in general for the gun, and the aforementioned lower value only for later guns that used SHS as AP (at 762mps or 2500 ft/s).

 

Thanks!

 

 

[MrDeaf]

They didn't?

8"/55 Mark 14 fires at 853mps
http://www.navweaps.com/Weapons/WNUS_8-55_mk9.php

8"/55 Mark 12 and 15 fires at 823mps
http://www.navweaps.com/Weapons/WNUS_8-55_mk12-15.php

 

Of particular note is that Mark 12 and 15 are built to lighter specifications.

[Phoenix_jz]

2 minutes ago, MrDeaf said:

They didn't?

8"/55 Mark 14 fires at 853mps
http://www.navweaps.com/Weapons/WNUS_8-55_mk9.php

8"/55 Mark 12 and 15 fires at 823mps
http://www.navweaps.com/Weapons/WNUS_8-55_mk12-15.php

 

Of particular note is that Mark 12 and 15 are built to lighter specifications.

 

That's what I'm trying to figure out. I've never seen the Mk.14 quoted as firing it's shells, AP and HE, at anything other than 853mps.  Later guns are where the varying between velocity begins depending on ammunition.

 

Yet for some reason in-game, the Mk.14 fires it's HE at 823mps instead of 853mps, which causes it's time to target to be be significantly longer than that of the AP.

[b101uk]

the Mk 12, 14 and 15 all have the same chamber volume, which differs from that of the Mk 9, 10, 11 and 13.

 

so logically the Mk 14 probably took the same propellant charge as the 12 and 15, but navweaps has it mixed in on the wrong page lumped with the Mk 9, 10, 11 and 13 that take a bigger propellant charge due to having a larger chamber volume.

[MrDeaf]

28 minutes ago, b101uk said:

the Mk 12, 14 and 15 all have the same chamber volume, which differs from that of the Mk 9, 10, 11 and 13.

 

so logically the Mk 14 probably took the same propellant charge as the 12 and 15, but navweaps has it mixed in on the wrong page lumped with the Mk 9, 10, 11 and 13 that take a bigger propellant charge due to having a larger chamber volume.

yeah, it even says on navweaps

" The Mark 14 was a relined Mark 9 with a fully chrome-plated bore and a smaller chamber. The Mark 14 was used for most regunnings during World War II. "

[Lampshade_M1A2]

It is possible that all of the 8"/55 guns fired HC (or rather all 260 lb shells) at 2,800 ft/s from a new gun with the common 2700 ft/s figure actually being the average muzzle velocity with a worn barrel.

 

Consider the range tables are AFAIK the same for all variants of the 8"/55 when firing the 260 lb AP shell.

[Murotsu]

According to both navweaps.com and the USNI World Naval Weapons Systems 1991 - 1992, the Mk 14 fires HC at 2700 fps, not 2800.