Bill,
You can make full length cases from 9.3x74R, but you would likely nave to anneal them pretty far back and fireform them several times to get them fully formed. 7x65R would also work but you would have different problems. I don't like to expand necks before fire forming due to the necks coming out uneven, but if you don't in this case, you would lose too many cases due to split necks. The 65 mm case is likely long enough to take the necessary trimming and still come out 60mm long. You can also use brass 410 cases, but everyone has 7x65R and 9.3x74R cases on hand and I don't know anyone that actually has brass 410 cases in their "pile".
Mike
