Nugentgl gives a longer overview and partial disassembly (around 66% he says) of their recently released Hephaestus T21 Gas Blowback Rifle, their second airsoft bullpup gas blowback project. This is a long one, over 43 minutes of video footage so you might as well heed his advice... "This is another long one so might as well get some food and a beverage before you press play..."