Maybe 1:10 is a nice touch, due to the present obsession with being "under-twisted." But the original 1:14 twist (or thereabouts) is plenty for any 9.3mm bullet made today.
Twist is beginning to be a marketing concept, though many don't understand the basic fact that it's also dependent on caliber. The "necessary" twist for long bullets isn't standard for all calibers, but directly dependent on a ratio to bore diameter. A 1:10 twist in .30 caliber is actually a pretty fast twist, like 1:8 in 6.5mm or 1:9 in 7mm--and so is 1:14 in .366.
