Bigriver,
The .270 WSM does not have a 300 fps advantage over the .270 Winchester, at least not when both cartridges are loaded to the same pressure, in the same length barrel. If you are getting 300 fps more in yours, it’s because you’re loading the .270 WSM to higher pressures or the .270 Winchester to lower pressures, or both. This is backed up by all pressure-tested loading data, plus the 4-to-1 Rule.
If you’re expecting similar magical results from the .325, you may get them. But most handloaders won’t.
