Looks to me like some sort of subcaliber adapter... it seems that the pistol cartridge is of smaller bore than the rifle (looking at the base and neck, respectively), which suggests that a special barrel (.32 ACP?) is contained within the adapter, and the bullet would be in free flight down the rifle barrel.

Hint- hint- it's one of the neat thingies that go bang featured as a "Cartridge of the Month." Find it (and others) with some history and pictures showing their nekkid intimate details over at http:CartridgeCollectors.org
They even have a PIAT cartridge there to arouse the Armorer..... My favorite is the Gyrojet, or maybe the .50 BMG flechette.

Apropos of nothing whatsoever... the Arsenal does have a Gyrojet cartridge in the Holdings of Argghh!

John S
Do have other photos of pop-out primer cartridges?

Cheers

9 x 51mm SMAW (Shoulder Launched Multipurpose Assault Weapon)

Well, that didn't take them long, John. I guess they have seen more of them than us!

The URL was of..HMM..some assistance.

Maggie's lipstick case?

It's a .22 getting fresh with a 7.62 trying to make a .38

Bloody randy Aussie rounds. I blame the fresh sea air.

It's a targetting round originally designed by the British for an anti-armour rocket. There was an automatic rifle with five rounds mounted parallel to the bore. You fired the sighting rounds until you hit the target, then fired the rocket. The one sticking out the back was based on the .22 Hornet case.

It's a targetting round originally designed by the British for an anti-armour rocket. There was an automatic rifle with five rounds mounted parallel to the bore. You fired the sighting rounds until you hit the target, then fired the rocket. The one sticking out the back was based on the .22 Hornet case.