RE: .270 grain bullets....
The 130 grain bullets will kill nearly anything you can hunt in the U.S. and do it well. The only thing I'd consider stepping up my bullet weight for would be elk or something larger. I'm curious if the two different bullets you shot were the same brand. You'll find by experimentation, that most rifles will have a brand and weight bullet that it seems to "prefer". The variation comes from the different tolerances each manufacturer maintains.
GH