Handloader Magazine, October 2004, had an interesting article on the 25 WSSM, and gave some loads. I loaded some sing this and got good results. I loaded 100 Horandady SP Interlock using 45 grains of IMR-4350. Got under 1MOA with this load, and took several deer with it. Very accurate out of my Browning A-Bolt.
For the 115 Barnes X-Bullet, it shows four loads:
Big Game 41 grains 2767 fps 2.60 Group @ 100
Hunter 44 Grains 2748 fps 1.09
IMR-4350 44 Grains 2856 fps 1.60
W-760 44 Grains 2837 fps 1.65
There are several other loads in there...........