If you want to keep it, try placing it in very, very hot olive oil and then between two wooden boards, and press like hell. I have heard tales of that straightening out bent coins.
If not, use Mother's Mag & Aluminim polish on it. This will make it look like the day it was minted. But of course, purest will tell you that polishing with any kind of mild abrasive will ruin the value of a coin. Given that it has been shot, I doubt it has any real value now anyway.
Good luck. Post pic when done.