Thread: Barrel-bore enlargement

I have a Sako 75 .308 std contour barrel and a Sako 85 7mm Rem Mag, std barrel also.
I want to use an ASE SL7 .30 suppressor for both rifles. I'm going to cut 2in off both rifles and get the same thread cut. I'm worried about the bore enlarging on the .308 barrel after threading due to not much barrel to cut into.(its about 16 mm).

So my questions are; What threads have people got cut on their Sako barrels? Has anyone experienced the barrel opening up on the end where the thread is cut? And do the ASE suppressors butt up against a shoulder cut into barrel or up against muzzle?

I read on Dean Maiseys website its common on buttoned-barrels to open up at the end.