Might also consider going Mystic Ranger with Sword of the Arcane Order and the Shooting Star sub levels, as this will get you 0th through 5th level spells off both the Sor/Wiz list and the Ranger list. You can combine your "scope" with Far Shot, sniper's shot, hunter's eye, and hunter's mercy, using a kaorti resin bolt (x4 crit multiplier) and the feat Telling Blow to add sneak attack to any crits. Also, consider Scout 3/Mystic Ranger 8, which while only netting 0th-4th level spells, also gives 11 levels of Skirmish, and IIRC either Evasion or Uncanny Dodge (hopefully the former, as you can nab the latter, and Improved even, with the full Primal line of spells, which are good all day buffs anyhow).
Assuming a modest CL of 12, that's 3d6 Skirmish, 4d6 Sneak Attack, 4x weapon damage, 4(dex mod x 1.5), one one shot, at triple the usual range (two doublings is a tripling, one from the scope, one from Far Shot, possibly a quadruple range shot if Horizon Goggles also stack with all this), out to ten range increments, with no penalty at all for range. Sound good?
EDIT : And this only uses two feats, meaning you can also have nice stuff like Darkstalker, Swift and Silent, and Mounted Shot if you're properly using phantasmal steed. You're basically capable of being the ultimate Hun.