Steve
The 325 WSM is a cool cartridge and certainly doesn't lack power, and I'd own one if I didnt already have a 7mmRM, a 30-06., 300WSM, and a 375 Ruger on the way!
However, I'm a rifle loonie, and you are more of a hunting loonie!!
For your purposes- Which is to up your power level over a 270 for larger/scratchy game- the 338 Winchester makes the most sense.
There is a HUGE selection of factory ammo, both premium and standard, as well as a HUGE selection of 338 bullets for handloading, brass is readily available etc. In short, feeding your rifle will be much more simple.
You can use heavier bullets with the 338, which will increase your "stopping power" more than using a ligther bullet that is faster.
There have been reports that the WSM cases don't feed as well in some rifles as narrower cartridges, which is more of a rifle issue in my opinion, but some guys have had trouble, although I've not experienced it wiht my 300WSM or any others that I have tried. You *may* be able to get an extra round int he 338 magazine, too.
Finally, I think the only large company that is currently chambering 325 WSM is Browning, and I know you (and I) are no a fan. Kimber is
chambering them and by all reports they are excellent rifles.
If it was me, I'd look for a 338 Winchester in a Ruger or Winchster rifle if you ca find a Winchester.
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