After the massacre of gay Americans having a good time at an Orlando nightclub by an Islamic terrorist there were vivid discussions about people owning an AR-15 -- the principle long gun in use in America -- despite the fact that it was not the firearm used by the murderer. For some the discussion immediately lurched to gun control, but a lot of people had very little knowledge to support their arguments. I thought we should take a look at the AR-15. (Note: I am neither a gun owner or member of the NRA.) Another issue about the gun came...