I would highly advise against any case with a metal exterior.
While the metal may look nice and appear strong, in my experience a metal case will come apart long before a plastic case will. Why do you think the military uses Pelican cases?
As an example, I have a hunting buddy who bought an expensive aluminum double rifle case. It looked like it was built like a tank. After just 2 years of airline handling and normal loading and unloading it looked awful, some of the rivets had started to loosen up and at least one of the corner protectors had been sheared off (by the airline). Broken latches and a sprung hinge.
As a comparison my cheap Plano case is still serviceable and is as good as the day I bought it, and it has seen essentially the same handling (including being flung off of a moving baggage cart onto the tarmac at the airport....I saw it happen and nearly s**t myself)
If you have the cash, the Pelican cases are just about indestructible. If not, I would go for one of the less expensive but sturdy Plano or Doskocils.
