I was thinking of trying some of the Lapua Mega (155gr) factory ammo in my 6.5x55 for deer huting this fall. My big question is whether anyone has experience with this bullet? I'm a little concerned that it might be too stoutly constructed (not open up fast enough) for deer. While I know I could could go with a lighter bullet, I'd like to stay in the 140-160 grain range out of principle- if I want a 120 grain bullet I'll just use my .257 Roberts!

There are also Nosler (partition or Ballistic tip),
Norma,
Sierra (GameKing, Don't forget or we have to suffer for another "MatchKing vs GameKing, are the first an hunting bullet or not" topic)
Speer,
Hornady, and a lot of other producers that sell bullets and that you can choose.