To the OP- Go Hunt!
I've used the Roberts a bit and wouldn't worry as much as some here. It doesn't need to have Barnes (or any other) mono-metal bullet to work. I like 115gr or 120gr Partitions and Hornady 117 or 120's. The extra weight helps penetration just like with every other caliber.
Lots of animals are taken with small caliber guns every year.
Be sure to post pictures when you get one.

“You never need fear a man, no matter what his size. When danger threatens, call on me, and I will equalize.”
Samuel Colt.

�Common sense is genius dressed up in work clothes.� - Ralph Waldo Emerson