Obviously you can't shoot down a V2 in flight phase; it's a ballistic missile. However, I have read an account of a Spitfire 14 pilot trying to shoot down a V2 on the launch pad as it launched. When he saw the launch crew running for the hills and then thought about what would happen if he actually hit it and set off all that HE and fuel in close proximity to his plane, he chose to break off his attack.