Double the Gun Apparently adding another barrel to existing firearms is the new rage today. First Arsenal Firearms introduced a double barrel 1911 and now an Israeli firm is introducing a double barrel AR-15: Israeli firm Silver Shadow are said to be debuting a double barreled AR-15 next month in Paris at the Eurosatory expo. Interesting. I wonder when the double barrel M82 will be released. Or better yet a double barrel GAU-8.