Just so everyone is aware, if the rcmp lab can make the rifle fire a single shot with an ar15 upper, to them its an ar 15. This has historically been done using wire and ductape. So if an AR 15 upper fits the brn 180 lower, and fires a single shot, and explodes as a result, yes, its an ar 15 lower. Thats just the ridiculous laws folks, thought youd all be used to the lack of logic by now.