In their 1912 catalog Westley Richards described both the rimmed .375 2.5" NE and the rimless .375 nitro express aka 9.5x57 Mannlicher-Schoenauer as "our .375 High Velocity Nitro Express Rifles". The Holland&Holland proprietary .400/375 is not even mentioned. The load for the .375 2.5" is given as 40grs Cordite/270 grs bullet - mv 2000fps, right on the money for the barrel inscription. As neither the rimless .375 NE nor the belted .400/375 H&H aka .375 Velopex will work in the clip-loading magazine of the 92/93/95 turnbolt Mannlichers, the rifle is certainly chambered for the .375 2 1/2" rimmed NE.