No, I'm sorry, Chris, for including that without the Nitro in front of it. Here's a bit from the Imperial War Museum that describes some Eley cartridges marked 360 Express that were in coiled brass cases.
https://www.iwm.org.uk/collections/item/object/30027656 (click the Show More to get the data) I suppose that the 360 2 1/4 BPE was so common that the 2 1/4 was not felt necessary and that no one would have expected Nitro loads in coiled brass cases anyway besides there not being room on the case heads for the 2 1/4. British proof houses were very strict about marking Nitro proofed rifles with "Nitro" and the Cordite load and bullet weight used.
