I just barely ordered a kevlar varmint in 308, its on the way. I haven't decided on if I want to go with the fixed 10x elite or the 6x18 buckmaster with turrets, as for the bipod, the regular harris should be fine, just make sure your stock is not touching the barrel when the bipod is mounted, so accuracy does not change, I have never owned a 550, I do have 2 527's that are my favorite rifles