30mm Cased Telescoped Ammunition

Can anyone ID the item in the photo?

Two holes on one side suggest it was on a display board at one time.

Provenance suggests possible Frankford Arsenal origin in the 1950s.

Cylindrical body is about 55mm (2 3/16") diameter by 1330mm ( 5 1/2") long with outer surface made of rolled aluminum sheet, not a drawn tube.

Small primer at the “base” end shows a firing pin mark.

The olive drab painted projection at the front attracts a magnet, and has a copper band at the lower end.

Entire object weight 19.6 ounces.

Anyone know or have any guesses? This will be donated for the IAA benefit auction eventually, but would like to figure out what is first.


That would be a great item for an IAA version of “Liar’s Club”! (…Thanks, Kitty Carlisle and now on to Soupy Sales…) I’m guessing the green annular material on the primer is an insulator for electric priming rather than a sealer?

TWAG: The nicely radiused groove would perhaps be for an O-Ring and the copper band for a hard wedge mechanical seal? Soupy is going to say it’s a device to provide for an emergency shut-off valve function. Picture it as a valve spool that stops the flow of something in a hurry.

Total guess and will be more than interested to learn what that thing really is…
Next up…?


I think it’s a cartridge for the US Army Chef’s 55mm Emergency Mashed Spud Gun Mk2. Inside is a potato masher on a piston. You load the 55mm cartridge with potato’s and place in the “Emergency Mashed Spud Gun Mk2.” on firing the Blank, the gases force the piston/masher forward at high speed giving you instant Mashed Potato’s.

Of course I may be wrong.

The projecting spigot looks very much like the back end of a 20mm projectile, complete with crimp groove and driving band!


Really cool item. I like Gravelbelly’s eye. It does look like the back end of a 20mm round or other big projectile base with driving band to me. Definitely wild what ever it is. Hope someone figures it out.


Armourer is correct. I have seen these in actual use.

The prototype, the T 276, and the Mk1, resulted in lumps, leading to the perfection of the Mk2.

The Mk2-1078 makes the gravy.


Obviously an Air Force item. The Army’s version used a waterproof fuze vs electric primer.

You’ve got me, but it looks an awful lot like the largest item under “Impulse Cartridges, Pressure Cartridges, Squibs & Igniters, and Gas Generators” on this page: tekord.com/products.htm Some sort of cartridge for propelling large payloads off of racks, or similar?

John S

Took the liberty of posting this over on BOCN. Those folks have some off-the-wall stuff and somebody probably has a case of them in their collection. Will report back as soon as I have an answer.

Call me a lair fellas…but what we have here is a flare

A countermeasure chaff/flare cartridge of some sort perhaps?

Here’s the first response from Dave on BOCN:

Hi it looks just like a CTA (Case Telescoped Ammunition) case with the projectile shoved into it the wrong way round. Does the projectile come out, if not my guess is it should?
The primer is struck on the one shown and it looks like there is a split up the side.
I’ve got a Philco Ford case that is fairly similar to this one, its fired also and also has a split up the side. The case dimensions are 42mm wide and 140mm long but the 20mm projectile (plastic banded) sites INSIDE the case.
Its a bit hard to work out the scale from your picture but they experimented in all sorts of sizes - there are 25mm and 30mm versions to name a few.
As for the holes in the side - it could have been mounted on a board?
I may be completely wrong with this idea, any chance of some measurements please and I’ll check it against a few of mine.

This may be it:

I think that Rick has gotten us pretty close.

I pulled on it and the "plug came out, and turned out to be a 30mm projectile!

Looking inside, the “bore” appears to go all the way to the “base”. It may be tapered slightly from base to muzzle (looser at the base end). At the base end there are four large cavities (about 5/8" square cast or machined into the solid piece which has been bored out.

The green around the primer appears to be electrical insulation rather than merely sealant. The seam in the side of the case appears to be a manufacturing feature, not a split caused by the pressure of firing, but may be associated with a spiral expansion scheme as discussed in the patent.

So, it appears that it is a “30mm Cased Telescoped Ammunition round.”

Rick’s Patent drawing is dated 1990, but mentions three from 1958-1961. I wonder if those may be closer to this version.

I just hope Rick shares his grand prize with the gentleman from BOCN…(very nice site by the way) While Soupy was way off, I bet it would make a mean mashed potato.

Great item, John and thanks for sharing it on the forum. Would someone care to add to this thread the basics on what the intended benefits of the telescoped design were?

Thanks, Dave

Yes, Dave,

I’m splitting all winning procedes 50/50. 'cause that’s the kinda guy I am. Really neat “round”. Had never heard of it 'til now.

Really great job Rick! You rule :-)

[quote=“DaveE.”]Would someone care to add to this thread the basics on what the intended benefits of the telescoped design were? [/quote]A smaller cartridge volume for a given performance. In particular, a shorter cartridge means a shorter and therefore lighter gun action, the action takes less space and could potentially be faster-firing.

John, could you tell us the precise length of the case in mm?

Case length about 1315mm