You may want to back off, just in case your approaching high pressures. What was the temperature the day you shot them? I know Texas never really cools off but, the pressure will probably go down some come fall and *ahem* "winter". As far as which group? Unless you plan on shooting 321.58 yards or more who cares?
Only thing I might be worried about with the second is an impact inside 100 yards or so with a Ballistic Tip moving about 3300fps, as Nosler lists the suggested max impact velocity for the Ballistic Tips as 3000fps. In that case, maybe the first group is best, or try out a 140gr Accubond or 130(?) Scirocco, or whatever.
