You can't make a bad choice so don't lose any sleep over your decision. Sierras have long been my favorite deer bullet so I'd probably go with the Pro Hunters, but like many others have said, Partitions are never a bad choice. Test all and go with whichever shoots the best in that Ruger. Good luck.
+1
I've had great results from the Speer 145 BTSP in my 280 AI and I'm sure you'll get even better at the slower speeds of the 7x57.
NPT is never a bad option, but I hold those for bigger game than whitetails personally.
