Here is my opinion, based on one shot, one animal. Just got back from Maine. Shot a decent buck, using my SxS 45/70 rifle with the 325 grain FTX at 2050 fps. Hit him at an angle, thru the last rib. He dropped in his tracks. When we butchered him last night, I found the off side shoulder badly blood shot, along with the empty bullet jacket and some lead fragments in it. Spectacular kill, but if it had been thru a shoulder first, or on a larger animal, I don't know. Seems that bullet went to peices in the chest cavity, without hitting any serious resistance. Now your shooting the same diameter bullet, at about the same speed, with 125 grains less weight, so I think its a safe bet the bullet may have expanded to quickly. Deer is probably dead, just not in your freezer. Goes back to the old fast lightweight bullets and their (sometimes) quick kills, and slower, heavier bullets that penetrate debate. I used the FTX's this year, because they regulated best in my SxS, but next time, it will be the old 405 grain softpoint load that has worked so well in my Marlin lever action.
Larry