Hi Ed - No real experience, but that short a bullet would stabilize in a 48" rate of twist at that velocity. That isn't much bigger than .58 & the US mil. did fairly well with 72", although the British 2-band rifles were more accurate with their 48" ROT.
Likely anywhere from 30" to 50" would likely work well with that stubby bullet. Closer to 50" would also shoot round ball at a decent vel.
Taylor's 16 bore Joseph Lang shoots RB well with it's 48" twist.

Buidling a DR?