A few yeas ago somebody, I think it might have been Boddington, did a comparison of the .270 Win. and .270 WSM. He used the same rifles with the same length barrels. He said that with some loads the WSM was faster and with others the .270 Win was faster. At the end of the article he said if he owned one or the other he wouldn't sell it to get the other, not enough difference.
