I have gotten fine results with both. The Swifts tend to retain more weight but expand wider, so overall penetration might go to the AB's, though I haven't tested them side-by-side. (I also tend to think deep penetration is perhaps the most overrated characteristic for most hunting bullets these days anyway.)
The Swift's jacket is pure copper, while the Nosler's is gilding metal, so in some bores (not all) the Swift tends to foul a little more.
