The nine lug Mk V is a big heavy action, not one I'd use for a LW gun. Maybe the six lug version with pencil barrel and light weight stock...
DF
The 6-lug action is pretty slick, but the 9-lug isn't too bad. My LH Ultralight in 270 WBY weighs right at 8 pounds with a VX2 3-9 in Talley ring mounts.