Krag'
I start with the basics.. good scope, solid rings, tight fasteners, parallax verification, solid rest....etc
Don't negate a good cleaning. I've had guns of known repute where accuracy began to fall off.......a couple passes with a bore snake and 10-20 foulers brings things right back.
I like to eliminate ammo from the equation early by starting with known good....
Midas +, Center X, Eley Black, and Federal Gold Medal UltraMatch (discontinued). Once you have proven the mechanics are solid with the above and ammo is removed from the equation....you can work towards less expensive stuff.
I've seen it take 10 shots between ammo swaps to get things to settle in.
I've had excellent results with Norma TAC and Norma Match.
