brewer-
I have a 30-06 load I developed for my rifle with 226gr bullet traveling 1850 or so fps. I shot a doe with it about 160 yds away, through the leg bone and through the heart. She did the 80 yd dash and died. Bullet gave complete penetration, entrance and exit.
Your cast load will work fine, I would aim for bone to break them down so they don't run so far. Shoulder coming or going, will work.
Where your short coming will be, is in determining distance to the target, so you can get an excellent shot. A pocket range finder for $100 is your best friend. With the cast velocity being lower, it will drop quickly at distance. Know your drop, practice at distance and go get one.