I like to error on the side of fast twist also. You can't overstabilize a bullet unless you are shooting very high velocities (3800+ fps) and using very frangible bullets which may come apart. But this is generally a problem with very fast .22 centerfires like the Swift, not a 300 or 7mm magnum.

You can figure the twist you want by using this formula.

Twist = 180 X D squared / L

D = bullet diameter in inches
L = bullet length in inches