My ultimate long-range varmint rifle:
It's a Ruger #1 action with a 28" Lilja barrel, chambered in .220 Swift. Standard twist for the old Swift is 1:14; this one is rifled 1:12 to better stabilize 60 grain bullets. The scope is a Leupold 6.5-20x.
My favorite load for it is a bit odd, in that I use a powder not commonly used in the Swift, Reloder 22. With the heavier bullets and longer barrel, it works wonderfully. I use either the Hornady 60 grain V-Max or the Sierra of the same weight. Velocities are in the low to mid 3,800's. Either load shoots honest 1.5"-2" groups - at 300 yards, where I keep it zeroed.