I load my own ammunition to customize my load to my shooting requirements. It is no more accurate than I can buy, but neither can I buy a more accurate round than I can load.
I guess I have not found the right store bought ammo yet, because my reloads, tuned to my pistols, are definitely more accurate than anything that I've pick up off the store shelf - especially some of the hopped up self-defense loads which my pistols like to scatter about the paper.
I found it interesting that higher priced cartridges did not equate to better accuracy. The pistol either "likes" or "dislikes" the round/load. I will add that consistency is an important part of the equation.