The Big Game Rifle Club merely specifies the .577/.450 Martini Henry "Express" load as requiring a maximum bullet weight of 325 grains, over and above the general class requirement for a minimum case capacity of 90-gr of Black Powder.

However, using the definitions required for "Class 3" (Double Rifles of .450 bore) Express Rifles for the Field Rifle Trials of 1883, this would also extend to;

* Weight not to exceed 8 lbs
* Barrel length not exceed 28 inches
* Powder charge not less than 4 drams (109.375 grains)
* Bullet weight not to exceed three times the weight of powder (this would require a Black Powder charge of at least 108.3 grains for 325-gr bullet.)

So - the 325-gr Bullet/90 grain powder load is not strictly an "Express" load, if you use the definitions of the day! AND - considering that modern Black Powders are down about 20% in "grunt", a 90-gr powder charge would come nowhere near developing true "Express" ballistics!

Accordingly, no .577/.450 MH rifles were submitted for the 1883 trials, and IMO, it ill-behoves The Big Game Rifle Club to re-write history!