it depends a bit on your usage, too. the swift has made a bit of a come back recently, but mainly in varmint weight rigs. it might be difficult to find many sporters in .220 . but virtually everyone chambers the 22/250 in a light weight model.

and if you think a 2 inch drop difference at 500 yards is critical, i'd love to know what your shooting at!!

the swift is a bigger case, burns more powder, brass is not as common and factory loadings are limited. both will see a barrel past peak accuracy by about 2000 rounds. ( early on, it had a bad reputation for burning throats, did the swift. but if you clean the rifle like you should, it won't be much worse than the 250).

personally, of the two, i wentfor the 22/250, just because of a broader choice of ammo and rifles. although i'd still like a No1 in .220 at some stage.