Having built quite a few .220 Swifts and .22-250's over the years, I am here to report there isn't much to choose from between them. Although the Swift can be loaded a little faster; if you try to handload it to speeds much above the .22-250, casegrowth and brass life become a significant issue due to the gently sloping case body and shoulder. Load both of them to around 3700 with a 55 gr. bullet and brass life is about the same. Both are capable of very good accuracy.

Within this class of calibers, the best of the lot is the .22-250 Ackley Improved - IMO. A little faster than the hottest Swift load and capable of providing very good brass life due to the superior case design. Or load it down to 3700 and get 20 reloads out of a case without ever having to trim it.