The .257 Scirocco 2 bullet has listed as "Coming soon" on Swifts site for a couple of years now. I know, I've been checking that page every couple of months or so. It's been rumored to be a 115 grain bullet but who outside of Swift really knows.
I have a very high opinion of Richard Graves bullets but it's difficult to compare his bullets BCs, which he will not publish publicly, with the BC of a still unreleased Swift bullet. Richard specializes in high quality, long for caliber, high BC bullets, unfortunately most .257 bores are designed for 120 gr and less bullet lengths. His are the first custom bullets that I'd look to but check with him on the required twist rates before ordering, he'll be straight with you.