25x105RR Unknown Cartridge


I share photos of my unknown cartridge. Listed in Hawkinson “Big Bore Ammunition” as unknown 3 diameter case.` I was told it is a Canadian experimental fin-stabilised projectile? Case has a blow-out base. The brass fuze and projectile are hollow. There is 2 wire bands on the projectile, I assume the knurl part would be seated within the case mouth.The perspex base has a 3/16"(5mm) hole in it and secured with a circlip.
There are no visible marks for Identification. I have 3 questions.
Is it Canadian? What device uses it? Approximate year of manufacture?
Any help appreciated. Enjoy the photos of an unusual item.


Ron - great round. I’ll have to dig it up, but there is patent info available in the Journal. It is Canadian. I’ve never seen a specimen that had the base disc and circlip.

I don’t know what platform it was designed for, but presumably a sub-cal training something akin to the Davey Crockett.



Hi Ron,

Great round! Thanks for posting.

Here is the patent mentioned by Paul: 2818811.pdf (264.9 KB)