ID CADs Round/Detonator

I came across this item that I believe is either a CADs round or a small percussion detonator from an artillery fuze or similar. It is made of cast pot metal with a hole bored through the centre and a percussion cap pressed into the top. There is a screw thread at the bottom. It is 24.5mm (.960") high and 20mm (.780") wide at its widest point. The precussion cap is brass and is sealed with reddish purple annulus. There are no markings of any kind. See photo below next to 9mm Luger round for scale.

Once I get back to work I can measure the thread at the bottom, this may provide more of a clue about its origin. (Whitworth = UK, Unified = USA, Metric = Rest of world).

Hi Falcon
Glad to have you as an IAA member.
Could you please explain CAD’s round for me?
Thanks & sorry but I don’t know what it is.


Pete–A CAD is a Cartridge Actuated Device round, such as a Bomb Release Cartridge or a Cable Cutter or an Ejection Seat Actuator. In other words it is a cartridge that does something other than fire a projectile meant to kill someone. However, there are CAD’s with projectiles, such as some of the Cable cutter.

Ron did a good enough job of explaining whats a CADs round is. One of my possible thoughts for this was a fire extinguisher discharging charge. From my experience these type of cartridges are hard to identify, as they don’t have as much collector interest as the “conventional” rounds.

The pot metal and very coarse threads at the bottom of the mystery item look like those on hand grenade fuzes. Grenade fuzes often include a spring-loaded striker to hit a percussion primer, so that also seems to fit.

Now you mention it, I think I may have seen something similar (fired) on an inert grenade. I’ve never really had much to do with grenades, to get a good collection in the UK you need to spend a fair amount of money.

I measured the thread on this today and it is a metric thread, OD 12mm with a 1.75mm Pitch. So that means recent British or any era European. I’d say after WW2 myself.