Those guns might be illegal in some areas, as they probably fall under the category of 'toy guns'.
Many jurisdictions mandate certain colors for toy guns - for instance in NY, the gun must have, at a minimum, a blaze orange insert in the barrel.
Now, I don't give a hoot about this, and I don't expect any of you guys to either, but it's something to bear in mind if the gun would have to pass through customs to get to you.
For instance, in the UK, you might get in serious trouble for importing a 'realistic imitation firearm'.
You may sneer at this, but laws like this are the reason that the UK is now a crime free utopia
