Since around 1950, I've had plenty-good accuracy and results with 53.5 grains of 3031 behind a 110-grain Hornady for varmints. 52.5 grains of 4064 behind most any 150-grain bullet, although I've used Sierras these last thirty years or so.
I've used Sierra's 165-grain HPBT and the 180-grain SPBT. All their bullets will give groups inside one MOA at 100 yards and 500 yards.
Not too long back I tried 54.0 grains of H414 behind a Sierra 180-grain SPBT, and put the first two shots about 1/8" apart (100 yards). The third bullet went into one of those holes, but I couldn't tell which. So I quit. I loaned the rifle to a buddy, and "interest on the note" is a bunch of elk steaks in my freezer...
You can load some 5 grains of shotgun smokeless or fast pistol powder behind an 00 buck for a squirrel load. You can use an 80-grain pistol bullet ahead of a bodacious quantity of 3031 and do horrible things to jackrabbits.

, Art