All rifles are different, even two of the same make and model can like different ammo. One thing I've found, though, is I've never heard of a rifle (or owned one) that didn't group well with one or the other of Barnes Vor-tx ttsx or Nosler Accubonds. Some rifles love both. The best bullet weight ballistically for the 30.06 is probably the 168 grain ttsx and the 165 grain Accubond. Both will do the job on anything in North America, but I'd go with something bigger to hunt the big bears. The ttsx is tougher and is a bit better suited to elk and moose, with full weight retention even after going through a leg bone on the way in, and the Accubond opens more consistently on longer shots...especially when passing through the ribs of a deer and only hitting meat. I use 140 grain Accubonds in my .270 when hunting deer, and 168 grain ttsx in my 30.06 when hunting moose and elk. If your buddy is mainly going for deer, I'd suggest
he try the Accubonds in his rifle first, and if he's focused on moose/elk, have him try the ttsx first. Both bullets will work on both deer and big game...but they each have their strengths and slight weaknesses that give them an edge depending on what you're hunting.