Hey, Dave gives some good suggestions, that you should take note of. But the biggest thing with bare chords is this: time. Everyone I know who has played guitar has initial problems with barre chords, something that just seems to fade with time. I agree with dave that you should perhaps roll your finger slightly, but not that it should have anything to do with the action of the guitar. Unless you have been attempting them for ages, I don't think you need to think of the the guitar as being at fault, it just takes time.