There is none.
There is no such thing as a Universal "best" bullet, "best" load or "best" anything else. If I can do nothing else with this post, it would be to banish the very concept of "best" from your mind forever. What works "best" in one situation will not be "best" in another. You need to sit down, assess your vulnerabilities, assess what your rifle is cable of, assess what you want it to do and only after you have made these decisions, start pursuing a load to meet your own particular needs.
About 70 years ago, the Army decided the "best" load used a 55 grain bullet. About 30 years ago, they changed that to a 62 grain bullet. For them, the "best" changed with a changing environment.
In my own case, I optimized a 223/5.56 loading for the various Ruger Mini-14s my family owned at the time. It was a Hornady 60 grain Spire Soft Point or 60 grain Spire Hollow Point bullet over 20.3 gains of IMR-4198 powder intended for use under 200 meters (the longest unobstructed distance on the land we owned at the time).
Please note that when I developed this load, 20.3 grains of IMR-4198 was well-below a maximum load. Subsequent loading manuals now show this to be a load that is above Maximum Load. If you are developing a new load, PLEASE follow proper load development procedures and begin with the Starting Load from a current manual and work up incrementally from there.
