For enthusiasts of NFA-controlled firearms (e.g., machine guns, short barrel rifles and shotguns, suppressors), the requirement to get the local chief of police or sheriff's approval on the required Form 1 or Form 4 has been a problem. Started at the inception of the National Firearms Act, the idea was to get the person in front of the chief or sheriff - who was expected to know the "problem children" in his or her jurisdiction - to keep wackos from getting these special weapons. In the 30s through the 70s, that was potentially appropriate: there was no national computer database available at all hours to get criminal histories.
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http://www.theoutdoorwire.com/features/225326