Update:
The period 56 grain Cordite “CERTUS” load (equivalent to .450/.400 3 1/4” tropical load) replicated with 66 grains of Reloader-15 and a 400 grain Woodleigh chronographs at average ~1920’/sec out of this rifle.
Pressure signs are normal.
I’m sure it worked just fine on the Tigers, Buffalo, etc. in India and Burma.
- Mike