I've found that my rage is good for one shot then needs to be cleaned to make sure the blades will swing freely. Once taken apart, cleaned and put back together they work fine.
It's simple to test. Move the blades out from under the o-ring, they should simply fall into place. If they don't somehting is preventing it, take apart, clean, replace and they work again.
You really need to do this to re-sharpen/replace the blades after a shot anyway.