RE: .22-250 vs. .220 Swift
Did the swift thing in the 70's with a Ruger M77V.
Not impressed, don't wish for it back at all.
Doing it again I'd go with the 22-250.
The 22-250 is plenty fast enough and got other things going for it.
Kinda find a 223 more useful than either of them-- specialized tools those two are.