Here is another good example. A sawed off short barrel show gun is illegal without a special license that is difficult and expensive toget. HHowever, you can buy one directly from a gun company absolutely legal with no special license if it has a pistol grip and no shoulder stock.. Why, because the law says to be a shotgun it has to have a shoulder fired stock. How do I know, I own one. Great for walking through the brush in grizzly bear country but a bad guy would use it for other things.. Crazy see what I mean