325 update
Just came across this thread and thought I would throw in my thoughts on the 325. I own the Montana 8400 scoped with the Leupy 2.5-8x36 B&C. bolted on with Talley one piecers. All up with Ching sling this rifle comes in at 7 lbs and a couple of ounces. One simply cannot argue with the fact that a cartridge that has a higher expansion ratio will push any given bullet faster with the same amount of powder, (or less), than a cartridge with a lower expansion ratio. Look at the 35 Whelen vs its parent, the 30'06. The Whelen will throw a 180 grain bullet substantially faster than the '06 using comparable amounts of powder. Some will cry "B.C., B.C., the 30 cal bullet has the higher B.C.", in the "real" world, and not the internet fantasyland many live in, the difference is nil between the two calibers for any given bullet weight.
The 300 "may" be more "versatile in one sense, and that would be the huge variety of bullets available in the .308 caliber. But to say that the 300 WSM is superior to the 325 as a large game round is simply not true. The 300 WSM is a great round, but in reality, it is the one of these two that doesn't fill any new niches, except that it lends itself to being chambered in lighter guns than the old standby 30 cal magnums. The 325 WSM OTOH, breathes new life into the field of choices for anyone desiring to use an 8mm bullet on game. And when the sun sets on the meadow at 10,000 ft. the bullet with the larger diameter, all else being equal, is going to kill better.
I bought my 325 for one purpose, I wanted a lightweight high country elk gun, and my Montana with its 24" barrel kicks 200 grainers out at 3000 fps. No holdovers out to 400 yards with the B&C reticle, serious thump on the far end, not too much on mine, and feels like i have the wings of pegasus on my back as I negotiate the rarified air of yonder mountains.
An aside, I've had a hard copy of that old FS study for about 30 years. IOW, it's Really old.
The ammo selections that were used??? Springfield Trapdoor 45-70 loads?? Too bad Randy Garret's bullets weren't available for the study, or Beartooth's Pile Driver's.Different results?
What is the old saw? Garbage in, garbage out?