It would be unlikely that anyone would pull apart some Vickers gun ammo to shoot in their double,
I havent claimed anybody did such thing., it was simply a response to those two who said they had never heard of
.303 175gn ammunition....nothing more nothing less.
As well, the Mk 8 ball load is not what you actually described:
Thats great, since nowhere have I said Mk8 and handloaded Hornady RN were the same thing.