RE: 25 WSSM
I've never shot/hunted with a 25wssm,but I have hunted withseveral 25-06s. To my way of thinking,the ammo is the cheapest componet of the hunt-and it really don't cost much more to go with premium bullets/ammo.
The performance of premium ammo is outstanding both in terminal bullet performance and accuracy. I would go winchester supreme ammo.