YOu've answered your question, with plenty of 223s in the safe, do this one in 222!! YOu'll be happy I promise.
10 twist in 223 will stabilize 69s so should easily stabilize 60 noslers. FWIW I have a 12 in my 22-250 and it stabilizes 60s easy, of course its got more speed too.
If you'll recall I shoot 223 and mentioned running 6.5 twist barrels to stabilize 90s for 1000 yards, same tube runs 52 bthps at 3400 fps and drops em in .5 moa groups at 200 yards. Not BR accuracy, but has not hurt me in matches either.
So I suspect that 10 will work fine, though for 60s I also bet that 12 would work, AND in a bind you can go to a 52/53 whichever it is, TSX for the 12 twist. TSX is equal (IMHO better) than the mentioned 60 nos part.
Jeff
