The .315 IOF, see:
http://ofbindia.gov.in/products/data/ammunition/sc/14.htm
is nothing else than the old Austro-Hungarian 8x50R (rimmed) Mannlicher used by the A-H armies during WW1 in their Mannlicher straight pull rifles. Same 244 gr bullet weight, same ballistics like the 1925 Kynoch “8 mm (.315) Mannlicher” load.