I've shot several elk with the Barnes X and Triple Shock 130 gr. bullets and also their 150 gr. bullets. I love them, never have recovered a bullet, always go clear through.
I love my .270, thus the username, and have it sighted in for a 200 yard zero and feel comfortable with it for shots out to 600 yards. Most places I rarely need longer shots than the 200 yards, but occasionally a 300- or 350-yard shot. I've shot metallic silhouettes at 600 meters with it with no problems. I generally use the 130-gr. bullets, but if in open country where shots may be long I use the 150 gr. bullets.
I've also had good results with the Hornady's, Speer's and Sierra's premium bullets, but they are not up to the performance of the Barnes, IMHO.
As already so well stated, shot placement is much more important than fps or diameter of the bullet. I don't take iffy shots, waiting for a good broadside or quartering shot or passing on it.