That was, from what I've read, the (presumed) reason for .375RNE (Rimless Nitro Express) being loaded with 2 grains less Cordite than 9.5X57MS (Mannlicher Schoenauer) per British references of the pre WW2 period; the presumption being that the 9.5X57 was intended for use on the European continent, the RNE for Africa, India, and such.

Every pre WW2 British proofed M1910 MS that I have seen (including my own cased Take Down Model) is proofed at "CORDITE 43 - 270 Gr MAX", the load for RNE. The 9.5X57MS load was 45 grains with same 270 grain projectile.