Y'all can argue your "theories" all day long but I have proven that coyota1 and Saskhunter know of what they speak. My 25# free-floated Remington 700 custom built bench-rest rifle with extra heavy varmint barrel will shoot the same hole all day long no matter hot it gets. My "factory" sporter barreled 700 in the original stock "barrel touching the stock" will shoot a 1" hole at 100 yds. no matter how hot it gets. HOWEVER when I put it in a free-floated stock it shoots complete different. First cold shot.. dead center. Second, third and forth 1/2 left 1 1/2" low all in the same hole. Then it starts walking farther left and lower until it's shooting 1 1/2" to 2" left and 2 1/2" to 3 1/2 low. Let the barrel get cold and it start the exact thing all over. Put it back in the original stock and it'll shoot 1" groups in and around the bull all day long. Your millage may vary.
Guns are not dangerous! People are! RKBA!