RFI - Rod in middle of brass shell casing?

Hello all,

I’ve recently come across a set of large empty brass shell casings (artillery and naval). Some of these brass shell casings seem to have a metal rod running through the centre and I’m hoping someone can explain what it is. All of the shells seem to have been fired so I’m honestly a little bit confused by what it is and how it works?

The photo below is an example of one of the larger shells I’m talking about.

Any advice would be greatly appreciated!!

Sorry, more photos below

The rod inside the case is called a flash tube. When seen from its side, there is a series of holes drilled along its length. Its purpose is to ensure that the propellant charge inside the case is ignited evenly when the primer charge is fired. This all happens in milliseconds.

The case in your photos is for a British 4.5" Naval gun. It was made by Edward Curran and Co. of Cardiff, Wales in 1966.

It was a separately loaded case, meaning that the projectile (the part which is fired from the gun barrel towards the target) was loaded first. The case was then loaded into the gun behind the projectile. The grooves around the top of the case held a screw-in cap which is blown out through the barrel on firing.


Thanks falcon!!

Seems like such a simple answer but surprisingly difficult to find if you don’t know what you’re searching for!

Really appreciate the help.


A very common question, which puzzled most of us until it was explained, so now we can help others who want to know. Good question, good answer.

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Dear forum members,

The photos show the artillery shell case with electric ignition. The primer sleeve with electrical ignition primer is mounted at the bottom of the artillery shell case. The main part of modern artillery systems operates on the principle of an electric ignition.

Indeed, some large caliber cartridges can be equipped with a flash tube, which provides ignition of the propellant in its central portion. The ignition of propellant in its central portion in some cases allows improving the ballistic characteristics of the shot. But this does not apply to large caliber artillery shells.

The propellant of large caliber artillery shells represents a combination of long powder tubes linked in a beam. This propellant cannot be ignited directly from the primer. To ignite the propellant, an additional igniter charge is used, which is located at the bottom of the artillery shell case and represents a black powder sewn into a cloth bag.


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A couple of images of flash tubes from gunbroker


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Looking at the photo again, that particular case has a shorter, wider tube attached to the primer. This was known as a magazine in British terminology.

That type appears to have had slits in the brass wall which were blown open on firing.

Here is a diagram of some similar earlier (1940s era) types with pre-drilled holes.

Wait_no_more: Could you post some photos of your other cases?


The drawing shows a primer for large caliber artillery shell with an additional igniter charge of black powder, but not sewn into a cloth bag, but placed inside a metal tube with holes, sealed with paper.
But this is not a flash tube, intended to ignite the propellant in its central portion.

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The flash tube was tired in some of the small arms also, but the advantage in burn was not great enough to over come the disadvantages in manufacturing the cartridge.

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Hi Falcon, thanks again for the help. As requested, two more of the shell cases below:

Left=tall shell, right=short shell

Left=tall shell, right=short shell

It’s interesting to see the different kinds. Originally I thought maybe someone had welded a metal rod into the shell so that it couldn’t be re-used haha.

Any info you can give would be great!


In the 4.5" cases such as this the primer tube ‘blows out’, causing it to bulge, making it very hard to remove once fired.

The other 2 cases you show are the 76mm OTO Melara Naval and the 105mm Artillery.
The 105mm has a ‘floating button’ type strilker in the tube, so these often look like they have not been fired as the actual primer is internal, the outer part (button) only transfers to strike.

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Here a sectional drawing of German DM231A1 primer.

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