I agree that the only way to truly determine the best ammo for a rifle, whether it be factory or handload, is to try it and see. Each rifle is an individual, and to wring the best performance, requires testing. The main reason that handloads are preferred is that they can be loaded exactly the same once you find the optimum load. With factory ammo, you can see major differences between lot nos. My favorite factory loads for my Remington 700 SPS Varmint are the Fiocchi Extrema 40 gr V-Max load, and the Federal American Eagle Tipped Varmint 50 gr load. They perform well in both my SPS and my Weatherby Varmint Special, as well as my S&W M&P 15.
NRA Endowment Member