If you get mesmerised watching slow-mo videos on YouTube, here is one for you. Gaosen Kinetics did a slow-mo of a Tokyo Marui Hi-Capa 5.1 Gas Blowback that has a cut-away firing... "Working on a longer video about outer barrels and thought I'd share some in-progress footage of a stock Tokyo Marui Hi-Capa 5.1 outer barrel in action in a cut-away slide - note how it drops and engages and disengages from the locking lugs in the top of the slide as it cycles, mimicking an actual short recoil action. Most people replace these with fixed outer barrels to add threading and better performance, as the locking and unlocking doesn't have a functional use in an airsoft replica."