Greenhorngal, I apologize for stubby.
What qualifies you to speak for me?
A statement was made and I simply asked the poster to back up his claim.
One of the reasons is that based on it's sectional density and balistic coeficient you cannot go wrong from varmint on up to deer and elk.
The 270wsm would actually be a very poor choice as a varmint cartridge as the recoil would be excessive,and throat erosion would be a concern for varmint hunting where many shots can be fired without allowing proper barrel cooling.As to sectional density and ballistic co-efficient,the 7mm's will match or exceed the .277" with a slightly heavier bullet(10gr more) which would actually be an advantage for elk hunting.