"Michael"FX has not released their slug liners yet. I don't believe the twist & choke of the current x barrels lend themselves to shooting slugs. They do however allow you to use a wider variety of pellets.
This is exactly what UA told me three days ago. I'm getting the 600mm Impact .30 with the current 1 turn in 30, and I don't expect it to like slugs. Tighter twists are expected later this year.
