can't help you on specific factory ammo, but I have had two 270 WSMs that I handloaded for.
The two bullets I liked the best with it were the 140 Accubond and 140 Barnes TSX (now I would use the TTSX though).
I killed bull elk with both of those bullets from that cartridge, and had zero problems.
I really liked the cartridge, and had a lot of confidence in it in the field.
My issue with the 270 WSM is that it is pretty overbore, and torches throats pretty quickly if you shoot a lot. Since you will be running factory ammo though you likely won't shoot the volume of rounds, unless you are made of money . Quality WSM ammo ain't cheap.
If you want to go over 140grains, I would recommend going up to a 7mm or 30.
