They have both the Protected Point and round nose in 160's SD 328 BC .509 so no slouch in that department. Cooking along at 2600 fps I don't think they would drop below Woodleigh's recommended 1800 fps minimum till about 350-400 or so yards.
They seem like the ideal bullet for a 1-8" 6.5-06, 6.5-284, or .264. I'm not sure the 6.5x55 can drive them fast enough to stay about the 2000 ft/s minimum operating velocity for that far. That would be my only concern.
Would be a real hammer out of a 26 Nosler or the 6.5x300 Weatherby.