I was reading the Nfa and some ATF rulings and a silencer is defined as a device used to lessen the report of a "portable" firearm. In an ATF ruling it was ruled that semi 1919s are not "portable". So can one build a silencer onto the barrel of a 1919 legally? I emailed the ATF and they did not reply. Don't plan on doing this just thought it was interesting but I must be missing something right?