The trouble here, and I'm not trying to be a jerk, is that you weren't sure what was beyond your target. While you knew from a pure safety perspective, you didn't know from a wounding and/or potentially legal perspective
As Peetza said, not trying to be a jerk either, but your bullet did just fine. I want an exit wound that allows for a lot of bleeding.
I think a 308 in 150gr would be fine if you want to go lighter but really, your current set up is just fine.