WE Katana system
An AEG system launched by WE in 2013, it is based on the AEG No. 2 gearbox combined with the PTW integral cylinder design, aims to realize some functions and features of the PTW in a more economical way.
The gearbox still uses gears with AEG specs, piston gear cut 3 teeth to fit the cylinder, WE does not do electronic fire control, but has a mechanical spring release lever linked to the insurance.
The cylinder adopts a bridgeless structure, with a special standard Piston, and the spring is a PTW standard.
Till 2020, the Katana system still has only the first three models of AR, and it is unknown whether WE will continue to develop it or not.
DAS（Dynamic Action System）
Developed by the Korean manufacturer GBLS, DAS means "Dynamic Action System", which uses an electric structure to achieve the motion effect of the gun and the recoil feedback similar to a real gun or GBBR.
This system is mainly aimed at the military and police as training equipment. In 2016, a batch of limited edition DAS M4A1 was released, which price up to 2,500 US dollars. The official entry into the Airsoft market is the mass-produced GDR-15 one year later.
It is derived from the structure diagram of GBLS, but it has never appeared in kind, so it should be one of the earlier design schemes.
The gearbox of DAS M4A1 and GDR-15 is same with GBLS’s structure. Although the same as Top EBB, it adopts the mechanism of firing first and then reloading, but the piston of DAS is a complete AR15 bolt. In order to simulate the real feeling of trigger, DAS Using a mechanical trigger instead of an electronic fire control, this is also the heaviest trigger AEG at present.
During shooting, the full-size bolt drives the buffer block to recoil and hit the end of the buffer tube to generate a more realistic recoil. The ammunition feeding system and Hop-up adopt a design similar to GBBR, which can achieve blot lock.
Due to the similar market niche, DAS is often compared with PTW. Obviously, DAS is much more popular, but its performance and system stability are not as good as PTW, besides the price is higher.
DAS is not limited to the AR platform, the products of this system also include K2, AK, 89-type rifles, etc.
However, at this stage, only GDR15 and 416 are sold to the outside world. In addition, GBLS also has an ongoing DAS pistol project.
AAF EBB（American Airsoft Factory）
AAF is a new factory and their system doesn't have a official name yet.
The structure of the gearbox is similar to the Top, but it is not a shell ejection gun. It may use standard AEG gears. The operation of the system mainly relies on electronic control. The early version of the ammunition feeding system had serious problems.
AAF is not a special magazine design like DAS. This system comes with an adapter that can convert AEG magazines into GBB feeding structures, and can use standard AEG magazines to achieve blot lock.
