Re: Scope Bell To Barrel Clearance?
That barrel won't expand enough from heat to touch a scope bell 2 thousandths above it. If barrels really expanded that much, their bore and groove diameters at that point would be large enough to cause serious accuracy problems. Folks shooting 26 to 30 caliber magnums once every 20 to 30 seconds for 20 to 30 shots get barrels very hot in long range matches. All bullets fired shoot well under 1 moa. There's more barrel and scope bell movement at that point from both whipping up and down when the rounds fired than any barrel expansion from heat will cause.
I'd get at least 1/16 inch clearance and more may be best on a hunting rifle. That way, if the rifle bangs around and something smacks the scope front bell, it will bend a little bit and still be usable after sighting in again. Otherwise, with near zero clearance, the bump may break the objective lens and then you get to use iron sights or buy the dream scope you've always wanted.