I've been reading up on the jump in performance the change to an Ackley Improved case can provide and the ease of forming brass for one.
Did PO Ackley invent a .303 Brit A.I.?
It strikes me that the long sloping nature of the .303 Brit could really benefit from the Ackley Improved technique.
If so, where could I get dies and load data for it?
Also, would a SMLE action take the increase in powder capacity and subsequent chamber pressure?