Help with .320/.250 Rook?


Would be grateful for help with a small cartridge, possibly a ‘Rook.’

Unfortunately; no headstamp.
Dimensions are:

Case length: 0.805"
Bullet diameter: 0.251"
Case head: 0.320"
Neck: 0.276"
Shoulder: 0.313"
Rim: 0.370"

I can’t find this caliber .320/.250 in any of the literature that I have and searching has been somewhat unsuccessful.
Have found .320/.230. in: “The Birmingham Cartridge Manufacturers” (CW Harding); Page 198.
Can anyone help with additional information?




I do believe this to be a .297/250 Morris cartridge. Basically a .297/230 Morris Long blown out to .250”

To my knowledge, there is no .320/250 cartridge.


Hi Guin,
The other option is the .320/.230, as described in: “The Birmingham Cartridge Manufacturers” (CW Harding); Page 198.

Many thanks for your reply…much appreciated.



Hi Sam,

It is a .300/.250 for Rifle based on the .295 or .300 Rook Rifle case. It was made by Kynoch.




Hi Fede,
I’ve labelled this as a “.300/.250 Rifle” based on a Rook case and added the manufacturer as Kynoch.
I’m grateful to yourself and ‘Guin’ for your assistance…it’s greatly appreciated.
I can now put this one; 'to bed.'


Hi Sam,

Think this is the correct box for your bullet (based on your .300/.250. comment) No contents so cant check anything else.


From the label that box was manufactured circa mid 1920’s, certainly prior to 1928.



Hi Eightbore,
Many thanks for the image…have attached it to the cartridge file.
Have avoided boxes in the past, because of space. However; can see that they are a vital part of the history and they have an; ‘attraction,’ all of their own.

It’s a very nice box…and I may have to think about getting more space!