ArmsEast is going to be producing barrels, Dlask already does and I believe ATR is looking at barrels (all of those currently sell stripped lowers, parts kits and uppers) I should note that assembling a lower is straight forward and the 'tools' are no big deal, but assembling an upper, while not rocket science, does require the correct tools. The tools are available from Brownells and for the time being they are exportable without permits or end-user certs.