1) Could this case be formed from relatively easily found .30-06 2.6 inch basic brass?
2) What is the operating pressure of the round and could the 9.3x62 duplicate it at the same pressure?

1. Yes, easily.
2. 63,800psi. Cannot get there with the 9.3 x 62.

9.3 x 66 splits the difference between the 9.3 x 62 and 9.3 x 64 Brenneke.

Don't tell me, you need it......*LOL*
If nomen est omen...... you own a .376 Steyr?? Me too! And man...... I LOVE it, ......really...... Until now it outperformed everything comparable with the handloads, I developped for it...