If I wanted a 9.3x63, I'd look at the following options:
- use a 30/06 case and "improve it" (blow out and sharpen the shoulder);
- use a 8x68 case and shorten and possibly improve it;
- do something with the 300 Win Mag case. Shorten and improve, possibly remove the belt; or
- use the 338 RUM case.
I have already done the 8mm ARP (8x67) using the RUM, and it really "booms".
Using the 8x63mm Swede case has its advantages and shortcomings:
- you better buy them while you can, as once they're gone, that's it;
- the brass is old and might not like being necked up. Annealing primed brass could be interesting;
- they are Berdan primed, and that has its own issues. No Magnum primers exist in Berdan (AFAIK); and
- case capacity is really no larger than a maximally improved 30/06.
- use a 30/06 case and "improve it" (blow out and sharpen the shoulder);
- use a 8x68 case and shorten and possibly improve it;
- do something with the 300 Win Mag case. Shorten and improve, possibly remove the belt; or
- use the 338 RUM case.
I have already done the 8mm ARP (8x67) using the RUM, and it really "booms".
Using the 8x63mm Swede case has its advantages and shortcomings:
- you better buy them while you can, as once they're gone, that's it;
- the brass is old and might not like being necked up. Annealing primed brass could be interesting;
- they are Berdan primed, and that has its own issues. No Magnum primers exist in Berdan (AFAIK); and
- case capacity is really no larger than a maximally improved 30/06.
