The old .333 Jeffery 300 gr. bullet has an s.d. of .386, next down the list is the 300 gr. .338" and the 550 gr. .458", both with s.d.'s of .375. Those are the highest I've been able to find. Note how a small increase in diameter, from .333 to .338, results in a big change in the s.d., so don't get too caught up in the numbers.