Boring machine bits should be .500". I've had some that were cut down T-augers, and they were too small, like .440", and you can never get them to chuck in the machine nicely. You should be able to straighten your bent bit. I'd wrap the shank end in something soft, like sheet copper, and clamp it in a vise and gently bend it in the direction it needs to go. I've even grabbed a bit while it was in the boring machine and given them a tweak, but that is risky.