Here's a couple ammo links that offer some legitimate LR stuff for the 270 WSM, don't know what is in stock but give them a ring. Gunwerks has the 150 VLD's loaded Gunwerks - Ammunition
HSM has Berger 150's and 130's loaded for Best of the West, I have used the 130's and shot them over a crony and they where better than expected as far a ES was concerned and they where right on velocity wise. And you can order bulk!The Hunting Shack, Inc. - 270 WSM
I would order two boxes of each and test them then order a case if one is up to snuff for LR work, one of the guys at work shoot the HSM stuff out of his 7mm and it is very good, I don't think I could much better.