Bill,
The original load was quoted as 43 gns cordite with 310 gn bullet for 2000 fps at 16 tons pressure and 2752 ft lbs energy.
Barrel length for that data was most likely 28 inch.
I have used this cartridge a fair bit and it is a good one IMHO.
I run the 310 Woodleigh soft and solids at 2130 fps from a 23 inch barrel in a modern double built with modern steel.

Also use 250 gn Hornady's and Woodliegh softs at around 2350 fps.
Recoil is very soft in an 8 pound double.
SD of the 310 grain bullets is .346.
Cases are available from Bertram or can easily be made from 9,3/74 brass.

Note. post edited as I've been informed that the Kynoch data I originally quoted was not correct.