As previously stated, because they are a highly endangered species and due to the harsh penalties imposed by the Lacey Act, I have never hunted tigers (and never will). It is clear that I have no personal experience in tiger hunting (as I do with lion and leopard), but from reading and studying them in videos, it is apparent that tigers are solitary cats and hunt alone, much like a leopard does. They are not pride animals, as are lions, and are are unlikely to congregate in a group long enough to be shot at. Especially after the first shot or two is fired.
I don't think i really understand your situation, but if you are speaking about captive, caged tigers, perhaps the wisest course is to build strong, high double fences separated by some distance and requiring two separate gates for the keepers to enter and leave through. Even the best enclosures can be defeated by a motivated cat, as the San Francisco Zoo incident of a year or two ago proved.
Should you expect a mass escape of 10 to 20 tigers, perhaps you would be best served by a mini gun or a Vulcan. I don't know if you are close to a Walmart, but I believe that are presently having a sale on their existing inventory of both mini guns and Vulcans, though they are limiting sales of 20mm ammunition to three boxes per customer. Why don't you email BATF and explain why you need the mini gun or Vulcan? I'm certain they would be sympathetic to your cause.
