This article says your rifle has a 1:12-inch right-hand twist:
http://dailycaller.com/2012/06/11/gu...varmint-rifle/
I wouldn't worry too much about the twist in bullet selection. Different rifles like different bullets regardless of twist. However, I suggest you start by trying the Speer 52-grain Hollow points. That is what shot the best out of my Savage .223 112BVSS out of all the bullets I tried, and I tried a lot.
The bonus is that those bullets are cheaper than many others (you can get them in 500 packs), and they explode varmints really well.