Just another tidbit on the Top Airsoft Japan shell ejecting M4A1 AEG... "Enjoy the Lock and load action with a charging handle. The bolt will be stopped after shooting the final bullet. With this motor-driven Ultimate Shell Ejection Blow Back AEG, you can enjoy shell loading, firing and shell ejecting just like a real M4A1. Also enjoyable without the shell ejection similar to the Marui AEG (you will need to install optional parts.) It is 100% full metal body."