WWII 5-inch/38 guns fire time-fused shells at surface/land targets

[Northstar98]

Hi everyone,

Ever since the Samuel Chase released (though this also applies to 5-inch/38 guns on the recently released Essex), the 3-inch/50 and 5-inch/38 guns only fire time-fused projectiles. This is appropriate to aircraft, but not to surface/land-targets, especially hard ones - where frequent airbursts are observed, which have little-to-no effect.

As such these guns should also have a point-detonating shell (common shell type with AA, but with a different fuse) or an armour-piercing/semi-armour piercing round available. The AI, at least for some ground vehicles, already seems to select ammunition more-or-less appropriately for whatever target they're engaging.

In the track below, while the target was eventually sunk, many of the rounds airburst short of the target. It's only when the round impacts before the time-fuse goes off when significant damage is done.

Another issue seen in the track below is that the 3-inch/50 guns do not track or engage the target at all, despite it being well within their range.

I would also recommend visiting this thread for dual-purpose naval guns more generally - IMO it's plenty relevant now (with nearly every naval gun with a calibre ≥76 mm/3 inch only engaging surface targets with only a point detonating/impact-fused shell available - lacking a proximity or time-fused shell).

SamuelChase_AirburstAgainstST.trk

[Silver_Dragon]

The main gun used on the Samuel L Chase (Arthur Middleton-class attack transport) carry 4x 3"/50 (7.62 cm) Mark 22 and a  1x Mk22 3in/50

The problem with DCS is that there seems to be a "standard" shell for all of them, with an anti-aircraft function that doesn't fit with reality. On fact, the SLC has only a bar with 40mm cannon ammunition

The 3"/50 (7.62 cm) Mark 22 has that ammunion:

• AP Mark 29 Mods 1 and 2
• HC Mark 27 Mod 1 1
• AA Mark 23 Mods 1 and 3 1
• AA Mark 27 Mods 1 and 4 1
• AA VT Mark 31 Mod 1
• Illum Mark 21 Mods 1 and 3
• Illum Mark 24 Mod 1
• Illum Mark 25 Mod 1

About AA ammo:

• The AA Mark 23 and its associated Cartridge Case Mark 3 were considered to be obsolete by the end of World War II. HC Mark 27 and AA Mark 27 were the same projectiles but assembled with different fuzes. These 3" (7.62 cm) HC rounds were unique in that they were the only ones of that type issued by the USN that did not have a base fuze in addition to a nose fuze.
   

Mk22 3in/50 ammunition:

• AAC Mark 34 Mod 10
• AAC Mark 35 Mods 1 to 12
• AAC Mark 47 Mods 0 and 1
• AAC Mark 49
• AAC Mark 52
• AAC Mark 56
• Common Mark 32 Mods 1 to 4
• AAVT Mark 31 Mods 1 to 11
• Special Common Mark 38 Mods 1, 2 and 3
• Special Common Mark 46 Mods 1 and 2
• RAP Mark 57 2a
• Illum 3a Marks 27, 30, 44 and 45
• WP Mark 46
• Chaff Mark 78

Projectile Description:

• Special Common had a windscreen with a thin hood and the body was strengthened to enhance its armor piercing qualities. Postwar, some Special Common were given a dye bag for spotting. Available colors were blue, green, orange and red.
• Common Mark 32 had a windshield but no cap.
• AAC Mark 35 and Mark 49 projectile bodies could be used with Point Detonating (PD), Mechanical Time (MT) or with proximity (VT) nose fuzes. When issued with MT or VT fuzes they were considered as being AA rounds, but when issued with PD fuzes, they were considered to be HC rounds. Changing the fuze also resulted in slight changes in the total projectile weight and burster weight. For example, the Mark 35 with a PD fuze weighed 54.3 lbs. (24.63 kg) total with a 7.55 lbs. (3.42 kg) burster. Controlled Variable Time (CVT) fuzes were introduced post-war. AAC Mark 35 could also be issued as B.L.&P. or as B.L.&T. for target practice. Projectiles that used MT or PD nose fuzes had an instantaneous contact type base fuze while a blind plug was used in place of the base fuze for those projectiles using VT nose fuzes. The AAC Mark 47 was designed as a heavier projectile using new, lighter weight fuzes so as to maintain the same overall projectile weight. However, the fuzes never appeared, so only a few thousand of the Mark 47 projectiles were manufactured.
• Window and White Phosphorous (WP) rounds were available, many as special Mods of the Illumination Mark 30, Mark 44 and Mark 45 projectile bodies.
• Chaff rounds were available for jamming different radar types. Chaff Load Mark 15 was for X-band while Chaff Load Mark 21 was intended for S-band. Chaff projectiles used a MT nose fuze that triggered a small ejection charge and the loads were dispensed through the base of the projectile.

About ammunition:

• Outfits listed are the design figures. Pre-war destroyers normally carried about 100 to 150 rounds per gun plus 100 - 120 illumination rounds per ship with the balance carried in magazines on Destroyer Tenders (AD). After 1940, outfits for most destroyers were increased to the design figure plus about 200 illumination rounds per ship. As the war went on, ammunition stowage on new designs was increased where possible. Some examples: Late war Fletcher (DD-445) class carried 525 rounds per gun in magazines plus 50 ready rounds per gun (these totals may include illumination rounds). The A.M. Sumner (DD-692) class carried 352 rounds per gun in magazines plus 50 ready rounds per gun. The A.M. Sumner class also carried 292 illumination rounds per ship in magazines plus 48 ready illumination rounds per ship. This was same capacity for the Gearing (DD-720) and Robert H. Smith (DM-23) classes. This large increase in ammunition weight over the design figures resulted in destroyers losing two to four knots in maximum speed from the design specifications. However, the stowage for pre-war destroyers could not be so greatly increased. For example, the Farragut class destroyer USS Aylwin (DD-355) had about 250 rounds per gun in magazines plus 50 ready rounds per gun in 1944. The rebuilt USS Selfridge (DD-357), which had traded her eight SP guns for five DP guns after receiving torpedo damage in 1943, carried about 43 ready rounds per gun and 260 rounds per gun in magazines. She also carried 22 ready illumination rounds per gun and 85 illumination rounds in magazines. By 1945, the new battleships in their magazines carried 500 rounds per gun, primarily AA Common and AA VT, plus 40 special types per gun. In addition, they had 55 ready rounds per gun. The older battleships that had replaced their mixed secondary batteries with a uniform battery of 5"/38 (12.7 cm) guns were able to store roughly the same number of rounds of ammunition as they had for the older guns. For example, USS Nevada (BB-36) during the Normandy operations in 1944 carried an outfit of 7,426 AA Common rounds (equivalent to 464 rounds per gun) vs. 4,830 5"/51 (12.7 cm) rounds and 2,400 5"/25 (12.7 cm) rounds. Ready rounds for all ships with base ring mounts were stored in the upper handling rooms which were located directly beneath each mount. Ships with pedestal-mounted guns had their ready rounds in splinter-proof boxes located near the guns.
• Outfits for most ships during the early part of World War II consisted primarily of AA Common plus illumination rounds. As noted above, changing the nose fuze type allowed these rounds to be used as AAC or as HC. The Porter (DD-356) and Somers (DD-381) classes as originally built with SP guns carried mostly Common rounds, but they did carry a few AA Common rounds which were intended for use against torpedo bombers and other low-flying planes. Starting in late 1942, AA VT projectiles were introduced and became increasingly available as the war went on. By the middle of 1944, most front-line ships had about three AA VT rounds for every one AA Common round. The usual practice was to fire this ratio at attacking aircraft. The smoke puffs created by the time-fuzed AA Common rounds allowed the fire control officers to assess and correct the accuracy of the firing control solution and also provided target guidance for the gun crews of the shorter-ranged 40 mm and 20 mm AA guns. VT fuzing reduced roughly in half the number of rounds fired per aircraft shot down. A notable success with VT ammunition was that of USS Abercrombie (DE-343) which shot down a Ohka (Baka) rocket glider bomb in May 1945, firing only two rounds.

From:
http://www.navweaps.com/Weapons/WNUS_5-38_mk12.php

http://www.navweaps.com/Weapons/WNUS_3-50_mk10-22.php