I ahve a pic. of the USS Bunker Hll in which the ship is described---

[dave]

length, beam, displacement, etc. Also says it has a battery of twelve 5-inch, 38 caliber guns. I have, in the past only seen naval guns described as 16 in., 5 in. etc. Have always thought that was the bore dia. or Cal.
So what's with this 5 in., 38 cal. designation?

[ray55classic]

I've seen similar descriptions before and wondered the same thing .

[barretcreek]

The bore is 38 diameters long. To distinguish from a 5" 54. Not sure how many guns were designated thus.

[Sunray]

"...this 5 in., 38 cal. designation..." Boat People speak. They talk about 3" 50's too. A 5"/38 is an obsolete deck gun seen on U.S. 'tin can' destroyers(Fletcher-class) like the USS The Sullivans, currently parked in down town Buffalo NY's Naval Park.
No mention of 12 gun batteries at all. There are 2 25mm Mk 38 guns though. Bunker Hill's main armament are the 122 missiles she carries.

[Art]

Bore diameter x multiples of bore diameter (calibers) indicating the length of the barrel has been the way naval guns are described for a very long time. The gun on the current Arleigh Burke class destroyers, which as Sunray indicates is a secondary weapon, is a 5" 54 Caliber automatic weapon meaning the bore diameter of this self loading piece of ordnance is 5" and the barrel length 54 times that equaling 270" or 22.5.' One of the few military designations that hasn't changed in well over 100 years that breech loading rifled naval guns have been in use. The reason for this being that a longer barrel gives the slow burning propellants used in artillery more room to burn and hence higher muzzle velocities.

[leftyo]

current 5 inchers are 5"62's. they changed them not too long ago.

[Art]

current 5 inchers are 5"62's. they changed them not too long ago.

You are correct, sir.

[dave]

Some seem to confuse the Bunker Hill with destroyers, it was a WW11 Carrier, never went to sea again after being hit at Okinawa. There must be another Bunker Hill, eh?

[leftyo]

probably been several. last one i know of was a ticonderoga cruiser.

- - - Updated - - -

https://navaltoday.com/wp-content/uploads/2015/07/BAE-Systems-Wins-Further-USS-Bunker-Hill-Works-1024x718.jpg

[Art]

Some seem to confuse the Bunker Hill with destroyers, it was a WW11 Carrier, never went to sea again after being hit at Okinawa. There must be another Bunker Hill, eh?

The 5" 38 was the heavy anti aircraft armament of most WWII ships commissioned after 1942 and many earlier ships that were subsequently refitted. The Bunker Hill (CV 17) carried 12 5" 38 caliber dual purpose naval rifles in four single and four twin mounts. The gun was a formidable killer of aircraft due partly to proximity fused ammunition and partly to superb optical and radar director fire control.

It continued in service on some U.S. and foreign ships into the early 1990s.

[dave]

Thanks for that, Art. I knew the were anti-aircraft guns, which I think was all any carrier had.

[Art]

CV-17_deck_as_laboratory_NAN1-68.jpg

Thanks for that, Art. I knew the were anti-aircraft guns, which I think was all any carrier had.

The gun was the main armament on destroyers and the Atlanta class anti aircraft cruisers. It was designed to be used against both surface targets and aircraft but on the carriers was almost exclusively an anti aircraft weapon. Interestingly a single mounted 5" 38 on an escort carrier scored a hit in the torpedo compartment of a Japanese heavy cruiser at the battle off Samar (part of the Battle of Leyte Gulf) that caused secondary explosions that disabled the ship. The picture shows two of the twin 5"38 mounts on the Bunker Hill. The other two twin mounts are on the other (forward) side of the island. The single mounts are below the flight deck with the medium and light anti aircraft batteries.

Interestingly some early aircraft carriers like the Lexington or the Japanese Kaga had heavy cruiser 8" gun armaments as built. Since the chance of an aircraft carrier having to engage in a line of battle gun surface action these were quickly removed in American ships and replaced with the much more versatile 5" dual purpose armament.