I've shot the 120NPT and the 110NAB at typical velocities, and preferred the 120NPT. It's a sweet little deer killer that I don't worry about if shot angles are bad. I also hunted with a 260Rem shooting the 100TTSX, which is same/same as a 257Roberts shooting the 100TTSX and it was a good combo as well. So long as you pick a well-constructed bullet, I don't think you can go wrong. My gut says that the 115/120NPT is slightly more "right" when shooting a Roberts, but that's just me and my way of thinking.
