30 Flanged nitro Purdey & 370 Cogswell:info needed

I am looking for some info about these cartridges.
Pictures and dimensional data will be very aprreciated


.370 Cogswell & Harrison belted:


Pivi…The .30 Purdey is a British designation for the .30 Krag and dimensions are the same. Two headstamps were used: KYNOCH 30-220 and KYNOCH 30 - P. John P-C is THE expert on this cartridge, hopefully he will see this post and add his comments…Randy

Hi Pivi - as Randy says - the .30 Purdey - full title ’ .30 Flanged (for Purdey rifles)’ was based on the .30 US Army made by Kynoch since 1898 - with lighter bullets to increase velocity & terminal energy - first with 170 gr and finally with 150 gr bullets - the last giving 2,700 fps instead of the original 2000 fps of the .30 US Army.

PS Armourer - where did you source the .370 C&H data??

Regards JP-C

Thank you.

.370 info from the ECRA data viewer.