Need your help!! Identify this naval shell

I was off the coast of Maui around two WWII landing craft that had sunk during training. One had been fitted with a tank turret, and there was a live round cemented to the site of the machine with those markings. Leads me to believe that it was some sort of tank round, the landing craft didn't have anything else to shoot it out of besides that. I'll upload a picture of it when i have it, hopefully my camera worked that deep.

Wow, middle-watch Thanks!! Now I have some googling to do! Thank you all for the info!

Hey, whaddaya know, I was right!

Has to be the bofors. Most RN "non gun" ships carried a pair either side of the Bridge, single barrelled. Ships with bigger guns such as the 4.5" usually carried Oerliken 20mm Cannon. The shell casings polish up beautifully and a lot ended up decorating fire places.

As mentioned earlier they are designated the 40/60 and unless memory plays me false the "60" referred to the barrel length.

Are you still wanting photographs? I have some circa 70's and 80's from the frigates I served on.

The only change from WW2 was the mounting was motorised and could be slaved to a spotter position. That used to be great fun, wait while some sprog midshipman was climbing on it then target it remotely and watch him hang on for dear life.

Watch any news clip of the Falklands showing an air raid and you will hear the very distinctive sound of the Bofors, like four loud knocks on wood followed by a brief pause as the ammo number slams in a fresh clip.

They were known as junk bashers and carried to warn drug runners to heave too, or sink them without wasting a missile. The normal round was HE with a tracer, but there was also solid shot, mainly for target practise or warning shots and "breakup" shot which was a clay type warhead designed to shatter as it left the gun. That was for battle practise when you did not want a solid round or a sheet of flame from a pure "blank" hitting the "enemy"

After the Falklands they were gradually replaced with rapid fire 30mm and high angle 20mm cannon.

Just to really bore you the Argentinian ground forces also had a version of the Bofors, it was mounted on a trailer and the wheels folded out to form stands. The Marines thought them brilliant and pinched them to take back for the Regiment.

and the AC-130 still uses the 40mm bofors

Hey we still have them fitted to some of our ships! Generally referred to as a 40/60 bofors.

The 40 mm anti-aircraft gun was often called a pom-pom, but the real name was Bofors gun, after the intial maunfacturer. Many thousands were built and even saw service in Vietnam mounted on a modified M-41 tank chassis as the M-42 Duster

Thanks guys. Does the gun have a particular name? I would like to get a photo of one if it's possible. By the way, the shell is spent, but it would be kind of mischeviously cool to have a live one!!!

QUOTE: Originally posted by Mikeym_us heck I have a 57mm US shell casing stamped 1943 and have no clue what it was used for its stamped M23A2 57mm Lot 42 F.A. 1943 and the primer is stamped M1B1A2 LS-3-51 also with a stamped 43 meaning 1943.

Anti tank gun shell.

heck I have a 57mm US shell casing stamped 1943 and have no clue what it was used for its stamped M23A2 57mm Lot 42 F.A. 1943 and the primer is stamped M1B1A2 LS-3-51 also with a stamped 43 meaning 1943.

The 40mm was fixed ammo meaning the shell and casing were all in one piece. The total length of a live round was somewhere around 18" maybe a little less. e said it was about 12" so that tells me it is a spent round, only the shell case.

kaaboooommm!!!!!!!! ouch!

Ummmm, I do hope there's nothing IN the shell?

I was a gunners mate in the navy in the late 60's. That shell case is from a 40mm cannon. The rounds were normally clipped together in clusters of 4 and fed into the gun magazine. It is the same gun used on most ships as far back as WW II as the main anti aircraft weapon. There were still ships that had them mounted when I was in the service. I personally saw them mounted on several Assault Ships at Little Creek Va. The 40mm was capable of firing around 120 rounds per minute but I doubt many loading crews could keep up that pace.

I know very little about this kind of thing, but if it's Navy and 40mm, it sounds like it might be ammo for those 40mm anti-aircraft guns you see all over battleships, carriers, destroyers, etc.