Which 117-gr bullet? I load my .257 Roberts with Hornady 117-gr RN, BTSP, SST, and flat base.
I load the RN at a mild 2,700 fps, so my .257 shoot just like my .30-06 with 180-gr RN.
It is a 24-inch barrel Remington 700 with 1:10 twist. For a hot load, I use a full case of 4350 or 4831 and that gives the best accuracy.
In the .257 Roberts, that is 45.0 gr H-4831 or 43.0 gr H-4350.
In the .25-06 would translate to about 52.0 grains of H-4831 or 49.0 gr H-4350 for the boattails and 2 gr less for the Sierra 117 Pro Hunter
Instead of dropping down to the 100-gr bullets, try the 110-gr Nosler Accubond with 49.0 gr of 4350 ( near max ). Expensive but accurate.