Need help identifying shell casing


Hi everyone!
I am trying to find out as much information as possible regarding the shell in the link below. I am trying to figure out what the meaning of the markings are, and am running into a few roadblocks. I am also wondering if this is possibly a British casing? This casing is up for auction along with many other military collectibles on July 25th with my auction gallery, and I am running out of time to set a reasonable estimate. Any direction or advice would be greatly appreciated! … ixjgf9.jpg


The markings indicate it was originally manufactured as a U.S.N. 5"/38 Mk5 case, made in 1945 at the Naval Gun Factory.

However, the markings also may indicate that it is a shortened drill or test case. How long is it?



Thank you for replying so quickly! The length is 16 inches.


An original 5"/38 case measures about 27" long. So, yours is one that was shortened. The presence of a case combination primer would tend to indicate it was used as a saluting or clearing round, or something similar, rather than as a test case that would have been fitted for a lock combination primer.

John S knows more about this stuff than I do and maybe he can comment if he’s logged in.



Does the word SHORT at the top also indicate that it was shortened, or does it mean it was made as a short?


I’d say that it was originally made as a full length service case. After it was fired, the empty was sent back to an Arsenal for re-loading and it was shortened at that time. Maybe because there was some damage to the case mouth or maybe just because.



The “Short” indicates it is a “short” case compared to the regular 5"/38 case which is 680mm long. The Drawing number next to it 329507 is provided for reference as to what it is.

The short cases are reported as 414 or 509mm long. They were made by shortening regular full length (680mm) Mark V cases, probably using cases too badly damaged at the mouth for reloading as full length.

The “short charge” or more technically correct “clearing charge” is used when the regular full charge fails to fire a gun. Since there may be some debris left in the chamber when the “dud” powder charge is extracted (remember, the explosive projectile is still in the barrel!) you don’t want any problems getting a new powder charge inserted and the breech closed as soon as possible so you can try to fire again, and clear the projectile from the barrel. Therefore, they make the special “short charge” for just that purpose.

Do not confuse the “short charge” with a “reduced charge” which used the full length case but a smaller powder charge for special purposes.

Most collectors seem more interested in the normal “full length” cases than in the short cases. yours has been highly polished, and probably will appeal more to someone looking for shiny brass decorative items than a fanatical ordnance collector who wants "one of everything.


Thank you both for this information. I should have known to go to the experts first, rather than off on my own tangent. You were both most helpful!



I’m glad to see that I guessed correctly on most of the details of the short case.

While having to clear a gun with a clearing charge may sound a little nerve-wracking to non Gunners Mate types, it was actually a safe procedure. That projectile sitting in the chamber is no more dangerous than one on a rack in the handling room or magazine. When it really got interesting was when the entire firing mechanism failed on a loaded round. There was no way to use the clearing charge until it was fixed. Sometimes the projectile could be jiggled out of the chamber and tossed overboard but other times the Gunners Mate had to work around it. I never had to deal with such an event, luckily. If I had, I would have insisted that the Gun Boss or other high-ranking Ordnance Officer was present, staring at the base of that loaded projectile right along with me. ;-) ;-)

Those were the days!



I can add that this 414 mm case was loaded with the 9 pound clearing charge for the 5" 38 cal. gun, while the 509 mm case was used with the clearing charge for the 5" 54 cal. gun.


Ray’s experience was mainly with the more complex 5"/54 gun mounts which used an automatic loader mechanism. Mine was with the 5"/38 which were very easy to manually open for removing the bad charge and loading the short charge.

With a cold gun, time was not critical, but given the very large number of rounds which were sometimes fired, if it was a “hot gun” situation there was a danger of the projectile possibly “cooking off” and it was a really good idea to get that fired out of the barrel as soon as possible.


Actually John, when I went to Gunners Mate school I was educated on the 5"/38 Mk12. There was a twin mount on the beach that we fired out into the ocean. My first ship was the USS Coral Sea with the 5"/54 Mk16 Slow Fire single mounts. I had one occasion when I was invited to shoot one of the brand new 5"/54 Mk 18 Rapid Fire guns on the USS Forrestal. Those guns were amazing when compared with the slow firing Mk12 and Mk16.

Sadly, guns on ships are mostly dinosaurs. Not many are left and they are getting fewer.

I’m surprised I can still remember all of this. I guess they taught me good.

Here’s a 5"/54 projectile that I rebuilt for my collection. It has features of both the early and later projectiles.