Im no powder pro and some of this could be complete bullshit but its how Ive connected the dots.
A 115 is on the heavy side of the 25 cal spectrum. Because it is a heavier bullet and slower to accelerate it will be in the bore a longer amount of time so I would go with the slower powder. If it were a lighter bullet it will be easier to accelerate and thus leave the bore faster so you want a faster powder that will fully burn before the bullet leaves.
If you have a slow powder behind a light bullet the bullet will be gone before the powder fully burns so youre just wasting energy and powder and likely wont ever have ideal velocities.
A heavy bulllet on top of a fast powder will burn all of the powder up before the bullet leaves the bore so youre not able to fully utilize the full barrel length and it instead acts as drag sort of, obviously the gases will still be expanding, just not like they would with a better suited powder choice. Youll be packing more powder in to achieve velocity and that can lead to over pressure.
In your example with a 115 the 4895 is 36 grains leads to 45k cup, drop that down to 33gr and its only 31k cup. Thats a big up swing in pressure. With the 4350 youre using 7gr more powder and only getting 44k cup at max, less pressure, and the low charge is 2 gr less but only 4k less pressure. That tells me that its not spiking up as much, a more even curve.
With that said barrel length could also play a part here, if it takes a 22" barrel to burn all the 4350 up but youre wanting a 16" barrel then maybe the 4895 will get you more velocity in that short distance than the 4350 will with its incomplete burn.
Quickload is designed for these sorts of scenarios, maybe one of these days Ill finally getting around to getting it to use to compare these things and be able to apply some numbers to situations.
Edit: and none of this addresses which your rifle prefers. Both powders would be functional. I would run a ladder of each and see if one gives a notably clearer ladder to make the decision easy on you.
Maybe the bore is .0005 larger than others creating less drag so the bullet will leave faster and thus your rifle would like the faster powder. Maybe the difference in bearing length between a partition and gameking could push you one way or another, lots and lots of variables.
