Re: 25 wssm or 25 wssm improved 40 degree or 25-284
A standard 25wssm would be right between a 25-06 & 25/284.
The 25-284 would waste barrels quickly. The 25wssm brass I've measured is as good as my Lapua 6br brass. It's just way too thick. Too thick to mess with improving in 25cal(if you plan to have enough barrel life left to actually use it). The 25wssm is fine for use as is.
I have a couple barrels chambered in 6.5wssm, and can't wait to use em. I'm blowing the shoulder 5deg steeper on it, just to bump capacity enough to compete. One barrel is just for fireforming/load developement.
For a 25cal, you would ruin a good thing to change capacity.