I've owned 6 .257s, 5 .25-'06s, and 1 .257 Weatherby. (Plus a .25-20 and a couple .25-35 but those don't count.) In my guns but 1, all nominally 1-10" twists, the 120 has outshot the 115. The exception was a Ruger 77 Mk II V/T, the first run of target gray rifles Ruger sent out. It liked the 115. It's possible with a different selection of powders, my results would have reversed, who knows?
I assume the 115 grain .257s are like the 95 grain 6mms ... for the 1-12" twist .257 Weatherby just as the 95s were first for the 1-12" twist .244 Remington. Just a guess though. I didn't look it up.
Tom
