The only failure-to-eject and failure-to-feeds with factory ammunition I've had were with limp wristing. It's common in polymer-framed guns. The mass of the frame alone just isn't enough to hold it still while the slide cycles.
[ame]http://www.youtube.com/watch?v=Jh9JhCyFFxA[/ame]
Squeezing the grip tighter will naturally lock the wrist, but can cause its own problems. I'm assuming you're right handed. Hold your right hand like you're holding a gun. Rest the bottom of your hand on your left palm. Now, push down hard with your right hand, push hard with your left. Now, with the fingers on your right hand, manipulate a combination lock, or roll a blob of clay into a ball, or do something else that requires a bit of dexterity in your fingers. You should have a locked wrist, but your fingers should be relatively relaxed. That's pretty much what you're looking for when you're shooting, especially with your trigger finger.
When you go to the range, do the same thing - use your shooting hand to push down into your support hand and your wrist will naturally lock up regardless of what you're doing with your fingers.
