Can't go wrong with any of them. I use 140s in the WSM and 130s in the 270 win. This is just how it ended up accuracy wise. As to the original question of why 130,140 and 150's. Jack O'Conner wrote that the 140's were made for people who can't make up their mind between a 130 and 150. I think he had it right.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli