has anyone on here wildcatted the 25 wsm yet? by simply necking down a 270 wsm? seems like this would perform better than the 25wssm and as good or better than a 257 wby mag. if a 25 wssm will meet or slightly exceed a 25-06 why not a 25 wsm?

The only problem I can see with this would be that the round (WSM) would be seriously overbore. The smallest I would want to go with the WSM case would be 6.5. Even in the most efficient of cases, there is only so much that can be done to push a bullet so fast. After a while the drawbacks of large powder usage for small velocity gain and worn out barrels out weigh just how fast you can push that bullet.

It would actually be slightly less 'over bore' than the .257 WBY mag. The WSM case holds a couple grains less powder than does the WBY case.

Go over to shortmags.org and ask away there. Those guys are short mag freaks.

Here is a link to some .257wsm threads.
http://shortmags.org/shortmags/snitzforum/search.asp?mode=DoIt