David, everything else being equal, always favor stick powder over ball. Usually cleaner, less temp sensitive and, with bare muzzles, less recoil. The only advantage ball powder has is for use in progressive presses turning out sheetloads of blammo.
ETA: Oh, and ball powder is usually cheaper.
Even then ball may not do better. From an old post:
In a Handloader (Number 152, July-August 1991 p.29) article about loading ammunition for the Palma matches Gary Sitton mentions this phenomenon. I'll paraphrase a bit.
Jensen's Custom Ammunition in Tucson, Arizona got the contract to load a quarter million rounds of ammo for the 1992 Palma Match. Cannister lots of AAC-2520, RL-15 and IMR-4895 were tested, and in keeping with eventual production methods they metered all of the charges.
AAC-2520 metered more uniformly, but the extruded powders did better on target which was consistent with general experience at long range shooting.
IMR-4895 was the eventual choice, and 600 yard groups fired from a machine rest ran .75 MOA from production ammo not tailored to the rifle or vice versa.
