Hopefully this is in the right forum 
  Your game has a life weight of 200-250 pound ( not a bear) 
Your range is 100 yards( not critical) 
Your rifle is chambered in 45-70 Govt. 
Your choice is a 405 gr Rem FN or a 300 gr Rem HP loaded to arrive at the target with similar Energy.
Grouping is not a criteria. 
Which would you pick? 
Is there any difference in in the performance( expansion)  of the various 300 gr HP?