I shot some of the Barnes 400gr SSSP yesterday, accuracy was excellent at 100yds, although I think I may have got a little bouce at recoil on the 3rd shot, that's with 50gr H4895, a near max levergun load, but I plan on shooting it with hotter loads on a future trip. It's also seated deep, they were loaded before I throated the 45-70 barrels, so velocity is down a little due to the longer jump, next loads will be to a longer COL and loaded well into the Ruger data.
I'll also be shooting it at 200-300yds!
Tim