In RA-Tech's new video, they show the new Bolt Airsoft B4A1 with the Bolt Recoil Shock System (BRSS) touted to be even better than Tokyo Marui's New Generation Blowback and Recoil System. It fires over 390fps on the average and they also show the internals of the AEG with the recoil system explained. The issue we see in their system is how can they adapt the system to other models with no stock tube.