I've put together a 6mm ARC Bolt gun off a Savage 10 action with a 24" barrel, 1-7 twist when the 6mm ARC first came out rather than going to the AR platform.
Tested a lot of powders. The following is the success I've had.
90-95 grain bullets – IMR 8208XBR – Decent velocity and great SDs
103-108...