The WE TTI M4’s lack any sort of functional gas tube which is integral to an AR15’s operation
The upper receiver of an AR15 fits onto the lower of the WE TTI M4
The stock trigger pack in the WE TTI cannot strike the firing pin of a AR15 bolt
The body of the WE TTI lower is several mils thinner than an AR15 lower, and shims would be needed for any AR trigger pack to work
The trigger pack of an AR15 appears to be able to fit onto the lower receiver of a WE TTI M4, one of the AR15 trigger pack retaining pins is impossible to insert without major modification, and the hammer isn’t operable with the WE TTI lower.
So essentially these Airsoft replicas cannot even operate an AR15 trigger pack without heavy modification with a precise tooling system operated by someone who knows the specific measurements to drill and tap the WE TTI lower receiver.
yet the ATF report reads:
On Feb. 8, U.S. Customs and Border Protection (CBP) officers at the Tacoma Seaport seized a shipment of 30 machineguns (M-4 automatic rifles) that arrived in a 40-foot ocean container on Oct. 20, 2009.
really. this is beyond me...