Dart guns can have some limited use depending on their type, power and range. They tend to have little regulation, but then again they are rarely deadly in their own rite. Tranquilizer dart guns do become available from time to time on the open market. These are commonly used by zookeepers, animal biologists and some veterinarians in their line of work. One drawback is that the drugs you need to make use of the guns are commonly restricted.
Some people take blowguns seriously, especially those in the martial arts circles. Maybe this is a little out of my element, but the whole ninja thing seems a but hokey to me. I have heard the stories about poison darts and whatnot, but the whole subject is to eclectis that I will not explore it in depth any time soon. Occasionally there are guns on the market that fire darts similar to those used by blowguns. While deadly to small animals, they are not manstoppers (although I wouls not want to be shot with one). If you have any real world experience with these and think you might have some valid input, then let me know.
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