Hi Stig,
I have a Sauer 202 Outback in 0.243" cal. fitted with a T8 mod. - 14x1 thread and 2mm clearance shoulder. As Flytie says the fluting on the barrel does not go all the way to the end, leaving a 1" plain piece before the muzzle suitable for a cut thread and the rear of the mod fits snugly on the barrel using a machined Delrin bush. The only thing you can't have with a fluted barrel is a spigot fitment which helps align the moderator - see "Jackson Rifles" website for details.
My only advice would be to go to a good gunsmith who will advise you on the best thread size/type and fitment to suite your rifle.
Willie