Been looking. Not interested in the 512. I feel the quality went down when they were bought by Tikka. Every barrel set I've seen (probably just my luck) have to be smith fitted on the 512's that weren't serialized the same (ie came with the receiver).
XM length action bartlein 9 twist 5r at 25" (11lbs)
162 AMAX over 52 gr rl-17 3.150 coal shoots one hole and runs 2875 (only have 25 rounds through this barrel-that will change drastically very soon!)
143 HH over the same charge (no change in seating die or anything) went .3 (haven't chrono'd...