Did you mean to say that it doesn't EXTRACT fired rounds from the chamber instead of " it won't eject" ?
If so, it could be a dirty or rough chamber. There could be something wrong with the chamber itself(too small, too big or headspacing problems). He should get it checked by a gunsmith or Remington to see whats what. My brotherinlaw had a 700 in 7mag that shot great. Ya had to have a block of wood to get the bolt handle back after firing it though. He ended up sending it back and Remington rebarreled it for free.
HWD