I had a 25 wssm for a few years. I used it only outwest and proofed to do a Great job on mule deer. It had very little recoil which was nice for I'm small build. Had gots of fun shooting prairie dogs with it. I reload the following.
For deer: 115gr. NOSLER BT with 44 grains of IMR 4350. VEl. 2940
For dogs: 87gr. SPITZER with 47 grains of IMR 4350. Vel. 3276
You can find more data at: data.hodgdon.com
I sold the rifle due to health keeping me from going outwest. I still have dies,2 boxes of Nosler 115 gr. bullets, 1 3/4 boxes of Speer 87 gr. bullets. 60 or so new cases and 200 or so primers. Anyone wanting to purchase this can reach me at firstname.lastname@example.org
Good luck with your 25 wssm, I sure did.